So who will join Hibs in the Scottish League Cup final on 13 March? Join us again tomorrow for live coverage of the second semi-final at Hampden Park between Celtic and Ross County.
In League Two, Annan Athletic stay in fourth place despite beating leaders Elgin City 4-2. East Fife move to within two points of the top side and leapfrog inactive Queen's Park after beating Clyde 2-0, while Arbroath jump above Stirling Albion into sixth after sweeping aside bottom side East Stirlingshire away from home.
In League One, only two games survived the weather and Peterhead's 5-1 thrashing of Albion Rovers takes them to within a point of second-top Ayr United, while Stranraer jump above Cowdenbeath into seventh place after beating Brechin City 2-0.
"We feel absolutely aggrieved. We are in a dogfight to meet the play-offs or worse and we need all the points we can get.
"I felt that we deserved to win the game and referee has made a terrible call that has cost us two points.
"The boy Cadden has gone for the ball, which he is entitled to do and I feel the referee will see that when he looks at that again.
"We have taken one point from the last three games and that says it all.
"We have to look below us and keep trying to take points."
"St Johnstone are a good, effective side, but I thought we put in a good team performance.
"I thought we limited them up front and our boys got the goals.
"From my angle, I thought it was a stonewall penalty.
"I am delighted for the boys and the manager - he gave us the belief that we could win today."
"Congratulate Hibs for reaching that final. They probably created more chances than us.
"I don't think that, on the day, we did ourselves justice.
"Especially on the ball, Hibs were better than us, but credit to us, we kept ourselves in the game.
"As the game went on, it was a bit scrappy and I thought we were the ones likely to win it.
"Then we lose a really bad goal and the players are 100% certain that it wasn't a penalty."
Will Celtic players Liam Henderson and Anthony Stokes be hoping that Ross County beat their parent club in tomorrow's second League Cup semi-final.
Unless the Highlanders cause a surprise against the Scottish champions, the pair will sit out the final under the terms of their loan agreement with Hibs from Ronny Deila's side.
"Emotional, excited, proud, all rolled into one.
"It was a really tough game.
"Two good teams out there giving it all and we just managed to get through.
"People in the past have called us bottlers. So much for bottlers.
"We are in the final of one competition and we have another tough game next weekend against our local rivals in another cup competition."
There were significant results in the Championship, with Billy King marking his debut on loan from Hearts by scoring a late winner for leaders Rangers against third-placed Falkirk.
That means the Ibrox side move eight points clear of Hibs, who of course were in League Cup semi-final action.
Meanwhile, St Mirren won their first home game of the season, coming from behind to beat bottom side Alloa Athletic.
Dumbarton 1-0 Livingston
Rangers 1-0 Falkirk
St Mirren 3-1 Alloa Athletic
Scottish League One
Peterhead 5-1 Albion Rovers
Stranraer 2-0 Brechin City
Scottish League Two
Annan Athletic 4-2 Elgin City
East Fife 2-0 Clyde
East Stirlingshire 0-3 Arbroath
"It was a difficult game and we are just happy to get to the final.
"We knew that, if we played at our best, we had a really good chance.
"You could see that St Johnstone found it hard to live with us at times.
"This is the kind of game you play football for and it was some feeling to score."
They were held at home, but the point moves Dundee into sixth place ahead of Inverness Caledonian Thistle. Motherwell jump a place and a point ahead of Partick Thistle, who slip into third-bottom place.
Hamilton end a run of nine games without a victory to move four points clear of second bottom side Kilmarnock. Accies jump up to eighth, ahead of Partick Thistle and Lanarkshire neighbours Motherwell.
Hibs are through to their 10th League Cup final and retain hope of winning it for a fourth time. A deserved victory against a St Johnstone side who were typically stuffy but typically lacking flair.
Saints midfielder Murray Davidson is yellow carded for hacking down James Keatings. That would mean a suspension for the final, but it doesn't look like it will matter anyway as we are into stoppage time.
Greg Kiltie passes up a fine opportunity to level, turning in the box but smashing the ball over the bar. Ali Crawford then hits a long range missile at the other end that Jamie MacDonald gets himself behind.