That's all from us on a night when the Old Firm cemented their place at the top of the Premiership, but the BBC coverage of the top flight continues in a few minutes when you can watch highlights of both tonight's games on Sportscene.
Former Rangers and St Johnstone defender Richard Foster join Scotland strikers James McFadden and Steven Thompson on BBC One Scotland from 22:40.
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Two-horse race confirmed?
Here's how the Premiership looks after leaders Rangers' stroll to victory over St Johnstone and Celtic's last-gasp win over Ross County in Dingwall.
The gap remains four points between the Glasgow sides at the top, with Celtic opening up an 11-point gap between themselves and Hearts that confirms it is now a two-horse race for the title.
Meanwhile, County stay ahead of St Johnstone at the bottom on goal difference now, but both remain two points behind Dundee, albeit they each have a game in hand.
County visit Livingston and Saints travel to Motherwell on Saturday, when Rangers get the chance to extend their lead at home to Dundee United while Celtic are involved in Sunday's League Cup final.
Join us then for more live coverage of another big weekend in Scottish football.
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Mackay 'proud' of County 'bravery'
FT: Ross County 1-2 Celtic
Malky Mackay thinks his side were unlucky to lose.
“Disappointed for the boys," the County manager tells BBC Scotland. "I thought they were terrific. I was very proud of them, especially with how brave they were in pressing Celtic high.
“We got a goal back and continued to press them. We have to keep our momentum going over our next games.
“It’s a measure of how this team are playing at the moment that Celtic are lucky to get away with three points."
'Seemed we were playing until they scored'
FT: Ross County 1-2 Celtic
Ross County manager Malky Mackay is bemused as to where so much added time came from when Celtic scored a late winner in Dingwall.
“It’s interesting," he tells BBC Scotland. "It’s the seventh minute of added-on time that Celtic scored in. It seemed to be we were playing until they scored to be honest.
"I think you see the relief from the fans and their management. It shows how happy they are to get away with anything from here."
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Postecoglou 'not worried' about Rangers
FT: Ross County 1-2 Celtic
Finally from Ange Postecoglou, the Celtic manager insists he did not have one eye on leaders Rangers' win at Ibrox over St Johnstone.
“It's just important to get the three points," he tells BBC Scotland. "I’m not worried about anybody else."
'Things potentially trying to derail us'
FT: Ross County 1-2 Celtic
Ange Postecoglou brushed off questions about the red card for Celtic centre-half Carl Starfelt.
“I think a few decisions went against us tonight, but I’m not going to complain about it - I just want to win games of football," the manager tells BBC Scotland.
"That’s what I tell the lads. We just keep doing our thing in winning games of football and not to worry about these other things that are potentially trying to derail us."
'We had to dig deep' - Celtic manager
FT: Ross County 1-2 Celtic
Celtic manager Ange Postecoglou believes his side deserved their win over County.
"Exciting finish, really pleased for the lads," he tells BBC Scotland. "After putting in an enormous shift, we found a way to get a winner and I think it was just rewards for their efforts.
“We weren’t settling for anything. It shows their spirit, especially with 10-men. We had to dig deep. I thought our football was good and we got the three points."
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Ange Postecoglou looked concerned in DingwallImage caption: Ange Postecoglou looked concerned in Dingwall
Fan fervour
FT: Ross County 1-2 Celtic
Could there be repercussions after fans spilled on to the pitch in Dingwall after Celtic's dramatic, late winner?
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Big win ahead of final
FT: Ross County 1-2 Celtic
Celtic's attention now turns to Sunday's League Cup final at Hampden against a Hibs side who ended their poor run by beating Dundee in the league on Tuesday.
Manager Ange Postecoglou's reaction to that narrow win in Dingwall coming up...
New Year fireworks in store
Six wins in a row for Celtic despite being under-strength because of injuries.
Rangers have won seven in a row in the league despite having changed managers.
It's all building up to a New Year derby cracker at Celtic Park, although there's still plenty of games to come between then and now.
'Ralston loves playing in this team'
FT: Ross County 1-2 Celtic
Billy Dodds
Former Scotland striker on BBC Sportsound
Quote Message: Ralston has been given a chance and he has grabbed it. He clearly enjoys the brand of football they're playing this season. The fans love it too
Ralston has been given a chance and he has grabbed it. He clearly enjoys the brand of football they're playing this season. The fans love it too
'Excellent' Celtic
FT: Ross County 1-2 Celtic
Pat Bonner
Former Celtic goalkeeper on BBC Sportsound
Quote Message: Celtic didn't do a lot wrong tonight. The way they played, in the first half especially, was excellent
Celtic didn't do a lot wrong tonight. The way they played, in the first half especially, was excellent
Saint Anthony
FT: Ross County 1-2 Celtic
Just when it looked like Celtic were going to fall six points behind the reigning champions, up pops Anthony Ralston.
The relief and elation of such a late winner led to a pitch invasion from some visiting fans - and no doubt we'll be hearing more of that later.
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'Saints need to bolster their squad'
FT: Rangers 2-0 St Johnstone
Richard Foster
Former Rangers and St Johnstone defender on BBC Sportsound
Quote Message: St Johnstone need to add to this squad. They need a freshness, something to come and reinvigorate them. It's five matches without a win in a row now. They look lost and shot of confidence
St Johnstone need to add to this squad. They need a freshness, something to come and reinvigorate them. It's five matches without a win in a row now. They look lost and shot of confidence
As you were at top and bottom
FT: Ross County 1-2 Celtic
This is the moment that ensured that Celtic stay only four points behind leaders Rangers at the top of the Premiership.
Anthony Ralston's late winner means County are still only ahead of bottom side St Johnstone - now on goal difference rather than goals scored.
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'Rangers were in cruise control'
FT: Rangers 2-0 St Johnstone
Richard Foster
Former Rangers and St Johnstone defender on BBC Sportsound
Quote Message: Nowhere near the excitement that was up in Dingwall in this one. It was a bit of a damp squib in the second half. That was probably the best I've seen Morelos playing this season. It was a good solid performance from Rangers. They were in cruise control for most of it
Nowhere near the excitement that was up in Dingwall in this one. It was a bit of a damp squib in the second half. That was probably the best I've seen Morelos playing this season. It was a good solid performance from Rangers. They were in cruise control for most of it
FULL-TIME Ross County 1-2 Celtic
That's virtually the last touch of the game and Celtic escape with a big three points.
It looked like Jack Baldwin's equaliser after Liel Abada's opener for the visitors would secure a surprise point for County, especially with Carl Starfelt being sent off.
However, Celtic so often come up with a late winner and this time it was Anthony Ralston's turn to be the hero six minutes into stoppage time.
'Tom Rogic, unbelievable'
Ross County 1-2 Celtic
Billy Dodds
Former Scotland striker on BBC Sportsound
Quote Message: Tom Rogic, unbelievable. You're desperate, you're down to 10 men and he dinks that ball in on his weaker foot. It's a massive goal in this game and in the season
Tom Rogic, unbelievable. You're desperate, you're down to 10 men and he dinks that ball in on his weaker foot. It's a massive goal in this game and in the season
GOAL Ross County 1-2 Celtic
Anthony Ralston
Wow!
It looks like Celtic's last chance had come and gone as Callum McGregor's cries for a penalty are brushed aside by the referee as his shot cannons off Regan Charles-Cooke.
And, from the corner, the ball is played out wide to Tom Rogic and the Australia midfielder's cross to the back post is headed home by full-back Anthony Ralston.
BBCCopyright: BBC
Post update
Ross County 1-1 Celtic
Now it's Celtic's turn to hesitate on the edge of their opponents' enalty box
Live Reporting
Clive Lindsay
All times stated are UK

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SNSCopyright: SNS Ange Postecoglou looked concerned in DingwallImage caption: Ange Postecoglou looked concerned in Dingwall 
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BBCCopyright: BBC
Latest PostWatch Premiership highlights
That's all from us on a night when the Old Firm cemented their place at the top of the Premiership, but the BBC coverage of the top flight continues in a few minutes when you can watch highlights of both tonight's games on Sportscene.
Former Rangers and St Johnstone defender Richard Foster join Scotland strikers James McFadden and Steven Thompson on BBC One Scotland from 22:40.
Two-horse race confirmed?
Here's how the Premiership looks after leaders Rangers' stroll to victory over St Johnstone and Celtic's last-gasp win over Ross County in Dingwall.
The gap remains four points between the Glasgow sides at the top, with Celtic opening up an 11-point gap between themselves and Hearts that confirms it is now a two-horse race for the title.
Meanwhile, County stay ahead of St Johnstone at the bottom on goal difference now, but both remain two points behind Dundee, albeit they each have a game in hand.
County visit Livingston and Saints travel to Motherwell on Saturday, when Rangers get the chance to extend their lead at home to Dundee United while Celtic are involved in Sunday's League Cup final.
Join us then for more live coverage of another big weekend in Scottish football.
Mackay 'proud' of County 'bravery'
FT: Ross County 1-2 Celtic
Malky Mackay thinks his side were unlucky to lose.
“Disappointed for the boys," the County manager tells BBC Scotland. "I thought they were terrific. I was very proud of them, especially with how brave they were in pressing Celtic high.
“We got a goal back and continued to press them. We have to keep our momentum going over our next games.
“It’s a measure of how this team are playing at the moment that Celtic are lucky to get away with three points."
'Seemed we were playing until they scored'
FT: Ross County 1-2 Celtic
Ross County manager Malky Mackay is bemused as to where so much added time came from when Celtic scored a late winner in Dingwall.
“It’s interesting," he tells BBC Scotland. "It’s the seventh minute of added-on time that Celtic scored in. It seemed to be we were playing until they scored to be honest.
"I think you see the relief from the fans and their management. It shows how happy they are to get away with anything from here."
Postecoglou 'not worried' about Rangers
FT: Ross County 1-2 Celtic
Finally from Ange Postecoglou, the Celtic manager insists he did not have one eye on leaders Rangers' win at Ibrox over St Johnstone.
“It's just important to get the three points," he tells BBC Scotland. "I’m not worried about anybody else."
'Things potentially trying to derail us'
FT: Ross County 1-2 Celtic
Ange Postecoglou brushed off questions about the red card for Celtic centre-half Carl Starfelt.
“I think a few decisions went against us tonight, but I’m not going to complain about it - I just want to win games of football," the manager tells BBC Scotland.
"That’s what I tell the lads. We just keep doing our thing in winning games of football and not to worry about these other things that are potentially trying to derail us."
'We had to dig deep' - Celtic manager
FT: Ross County 1-2 Celtic
Celtic manager Ange Postecoglou believes his side deserved their win over County.
"Exciting finish, really pleased for the lads," he tells BBC Scotland. "After putting in an enormous shift, we found a way to get a winner and I think it was just rewards for their efforts.
“We weren’t settling for anything. It shows their spirit, especially with 10-men. We had to dig deep. I thought our football was good and we got the three points."
Fan fervour
FT: Ross County 1-2 Celtic
Could there be repercussions after fans spilled on to the pitch in Dingwall after Celtic's dramatic, late winner?
Big win ahead of final
FT: Ross County 1-2 Celtic
Celtic's attention now turns to Sunday's League Cup final at Hampden against a Hibs side who ended their poor run by beating Dundee in the league on Tuesday.
Manager Ange Postecoglou's reaction to that narrow win in Dingwall coming up...
New Year fireworks in store
Six wins in a row for Celtic despite being under-strength because of injuries.
Rangers have won seven in a row in the league despite having changed managers.
It's all building up to a New Year derby cracker at Celtic Park, although there's still plenty of games to come between then and now.
'Ralston loves playing in this team'
FT: Ross County 1-2 Celtic
Billy Dodds
Former Scotland striker on BBC Sportsound
'Excellent' Celtic
FT: Ross County 1-2 Celtic
Pat Bonner
Former Celtic goalkeeper on BBC Sportsound
Saint Anthony
FT: Ross County 1-2 Celtic
Just when it looked like Celtic were going to fall six points behind the reigning champions, up pops Anthony Ralston.
The relief and elation of such a late winner led to a pitch invasion from some visiting fans - and no doubt we'll be hearing more of that later.
'Saints need to bolster their squad'
FT: Rangers 2-0 St Johnstone
Richard Foster
Former Rangers and St Johnstone defender on BBC Sportsound
As you were at top and bottom
FT: Ross County 1-2 Celtic
This is the moment that ensured that Celtic stay only four points behind leaders Rangers at the top of the Premiership.
Anthony Ralston's late winner means County are still only ahead of bottom side St Johnstone - now on goal difference rather than goals scored.
'Rangers were in cruise control'
FT: Rangers 2-0 St Johnstone
Richard Foster
Former Rangers and St Johnstone defender on BBC Sportsound
FULL-TIME Ross County 1-2 Celtic
That's virtually the last touch of the game and Celtic escape with a big three points.
It looked like Jack Baldwin's equaliser after Liel Abada's opener for the visitors would secure a surprise point for County, especially with Carl Starfelt being sent off.
However, Celtic so often come up with a late winner and this time it was Anthony Ralston's turn to be the hero six minutes into stoppage time.
'Tom Rogic, unbelievable'
Ross County 1-2 Celtic
Billy Dodds
Former Scotland striker on BBC Sportsound
GOAL Ross County 1-2 Celtic
Anthony Ralston
Wow!
It looks like Celtic's last chance had come and gone as Callum McGregor's cries for a penalty are brushed aside by the referee as his shot cannons off Regan Charles-Cooke.
And, from the corner, the ball is played out wide to Tom Rogic and the Australia midfielder's cross to the back post is headed home by full-back Anthony Ralston.
Post update
Ross County 1-1 Celtic
Now it's Celtic's turn to hesitate on the edge of their opponents' enalty box