St Johnstone 0-2 Dundee Utd
Dundee United moved to within three points of third place in the Scottish Premier League with victory over 10-man St Johnstone at McDiarmid Park.
Scott Robertson steered home a low strike on 31 minutes, following a terrible miss from Willo Flood.
St Johnstone striker Francisco Sandaza was sent off for a retaliatory kick early in the second half.
And United were content to hit on the break, with a sweet John Rankin strike settling the match in injury time.
The win stretches United's unbeaten run against the Perth side to 16 games and is their seventh win in their last eight league outings.
Saints, who drop to fifth, handed a debut to recent signing Derek Riordan and the former Hibs forward was busy in the opening minutes.
United goalkeeper Dusan Pernis awkwardly scooped away a low, curling free kick from Riordan and Cillian Sherdian could only slam the rebound against the post from close range.
Riordan then produced an excellent cut-back for Murray Davidson on edge of penalty area but the midfielder shot straight at Pernis.
It took the visitors 10 minutes to muster a threat as Robbie Nielson popped up at the back post to meet a teasing delivery from Paul Dixon but the full-back was let down by his chest control and a good chance was squandered.
United should have been in front five minutes later when St Johnstone keeper Alan Mannus fumbled under pressure from Gavin Gunning and Flood somehow blasted over the crossbar from inside the six yard box.
Flood later whipped in a great delivery for Jon Daly but United's top scorer saw his header flash narrowly wide of the target.
Soon after, Daly was involved as United took a deserved lead.
The Irish striker did well to hold up a long ball and lay it into the path of Rankin, who had his progress halted by a defensive block. Robertson knocked the loose ball on and it came back to him via Rankin before the midfielder drilled in an angled finish from 16 yards.
Gary Mackay-Steven set off on a gallop from his own half but David McCracken made a vital tackle, only for Mannus to make a hash of his attempted clearance. The ball fell for Daly but he couldn't get the ball under control in time to punish the keeper.
Mannus continued to look nervous when failed to gather a Flood free kick and he was scrambling to keep out a venomous long-range strike from Dixon at the end of the first half.
St Johnstone's cause was dealt a huge blow on 57 minutes when Sandaza was shown a red card for his reaction to a challenge from Sean Dillon.
Having been ordered off by referee Euan Norris, the Spanish striker exchanged a few heated words with the United defender before angrily shoving team-mates Jamie Adams and Dave MacKay.
With St Johnstone reduced to 10 men, United were content to sit back and hit on the break as Daly headed wide and Robertson warmed the palms of Mannus with a stinging shot.
A Dixon cross was then knocked down by Johnny Russell but Daly's effort on the turn flew wide.
In the third minute of injury time, Rankin strode forward and fizzed a cracking strike out of reach of the diving Mannus to double the margin of victory.
St Johnstone manager Steve Lomas: "Fran has kicked out, for whatever reason.
"He's let his team-mates down today. I'm a big fan of Fran and will back him to the hilt, but you just can't kick out on a football pitch and he left us a mountain to climb.
"We as a club just can't afford to play against a full strength Dundee United with 10 men.
"I thought the lads that were left out there battled manfully and they got the second when we were just throwing everything forward.
"It's disappointing, we're all gutted, but Dundee United are only two points ahead and it's going to change week by week.
"It puts pressure on now to go and try to get wins away from home, which isn't easy, especially at Motherwell, Celtic and Hearts.
"We're under no illusions, but one thing I do know is our boys won't throw the towel in."
Dundee United manager Peter Houston: "It's a huge three points for us today but it doesn't mean we're going to end up in the Champions League.
"St Johnstone in the first five minutes could've scored two goals and for the rest of the 35, 40 minutes we started creating chances.
"I don't think the sending off helped us in many ways. We were getting a wee bit jittery near the end, so the goal was nice but I was hoping he (Rankin) would've taken it into the corner."