Paul Dixon headed a late winner as Dundee United came from behind to beat Falkirk and reach the Ladbrokes Premiership play-off final.
Dixon's goal sealed a 2-1 victory at a sold-out Falkirk Stadium and a 4-3 aggregate triumph to keep alive United's hopes of returning to the top flight at the first time of asking.
James Craigen fired home his second goal of the tie inside 11 minutes and the game remained nicely poised, although Falkirk appeared to have taken control before Simon Murray levelled with 14 minutes left after the hosts failed to deal with a simple ball forward.
And United completed the comeback with three minutes left to set up another two-legged affair next week against either Inverness or Hamilton. Substitute Alex Nicholls collected the ball from a throw-in on the right and had space to cross to the back post, where Dixon beat Tom Taiwo to loop a header into the far corner.
The hosts had taken the lead for the first time in the tie after a crisp move. Right-back Aaron Muirhead played it into John Baird's feet and the striker laid it off to Craigen, who arrowed a 20-yard drive which went in off the far post.
Falkirk were buoyed by the goal and had some good passages of play inside the United half with former Tannadice midfielder Mark Kerr making them tick but United were getting forward too and they created their first clear chance when Dixon's cross found Thomas Mikkelsen in space. The Dane headed over from 10 yards.
Murray twice fluffed chances to shoot from about 18 yards before some balls over the top caught out Falkirk, but Mikkelsen could not find Murray from the first break and curled not far over from 20 yards from another opening.
There was controversy in the 50th minute when referee Kevin Clancy blew for a very soft free-kick just as William Edjenguele volleyed in off the bar following a corner. Mikkelsen had placed his hand on Watson before heading the ball on but the defender went down very easily.
United kept up the pressure and Andreu stabbed wide following a cutback by Murray, who soon had a header saved by Robbie Thomson.
Falkirk responded and Craigen and Luke Leahy twice linked up well to threaten.
Thomson got down well to save from Murray but the Bairns were now keeping United at arm's length and visiting manager Ray McKinnon made a tactical switch midway through the half, taking off striker Mikkelsen and bringing on midfielder Scot Fraser and moving to a 4-2-3-1.
The equaliser came from a simple diagonal ball from Fraser from inside his own half. Blair Spittal won it in the air and Murray got the ball amid some hesitant defending from Muirhead before calmly slotting home.
Spittal took a yellow card to stop Myles Hippolyte on a dangerous break and the Falkirk substitute could not clear the wall from the free-kick.
Extra time looked likely but Dixon soon struck to spark wild celebrations among the visiting fans.
Dundee United manager Ray McKinnon: "The desire to win games recently has been outstanding. "They should have won the last 10 games in my opinion and I think they got their just rewards tonight.
"We are definitely a team that's in form and the benefit for us is that they (Inverness and Hamilton) have to play their strongest sides on Saturday. There is no resting players for them.
"In effect we have got an extra day recovery on them so hopefully we will be bang at it on Thursday night.
"I haven't seen that fatigue yet. We have got a lot of injuries, (Thomas) Mikkelsen and even Simon Murray was feeling his hamstring, Willo Flood's hamstring, and we have full-backs missing. Scott Fraser has been out with a broken metatarsal and he felt something click and had to come off.
"But the character there is different class and I honestly don't think they feel tired. I said to them at half-time you are the fittest you have ever been.
"They are fit boys, they are good professionals and they have given themselves a chance."
Falkirk boss Peter Houston: "It's heartbreaking for the players and the fans and I'm really disappointed we couldn't take it that step further.
"We have to evaluate the season and try and bring in a wee bit of quality here and there if we can and go again next season.
"That's Hibs, Hearts and Rangers out the league now and good luck to Dundee United in the final, I hope they do well."