Championship - Swansea reach play-off final
After a 0-0 draw in the first leg of the semi-final at the City Ground last week, goals from Leon Britton and Stephen Dobbie gave the home team a 2-0 lead at half-time and in the tie overall.
That looked likely to secure them a place against Welsh rivals Cardiff City or Reading in the final on May 30 at Wembley Stadium, but Forest had other ideas as they mounted a furious attempt to restore parity.
They hit the post in the first period and the bar in the second before substitute Rob Earnshaw gave them renewed hope when he swivelled to fire home from inside the Swansea box on 80 minutes.
Forest were also denied a stonewall penalty two minutes into injury time when Ashley Williams clearly blocked an Earnshaw volley with both hands, but that was missed by the referee and his linesmen.
Earnshaw cracked a shot against a post in the final minute of the match before substitute Darren Pratley finally won it for Swansea when he walloped home from the halfway line deep into stoppage time after the ball had broken favourably to him with Forest keeper Lee Camp stranded in the opposition box from a late corner.
Pratley's clinching goal sparked wild scenes of celebration in the ground with home coach Brendan Rogers embarking upon a Jose Mourinho style celebration along the home touchline. They are within one more win of ending their 28-year exile from England's top division.
It was difficult not to feel for Forest, who deserved to force the match to extra-time having dominated large swathes of the second half against a stylish home team.
Forest could have been ahead on five minutes when David McGoldrick saw a shot clip the bar and fly over after he had been played in by Nathan Tyson.
Fabio Borini did likewise at the other end when his shot deflected off Wes Morgan and hit the bar with Camp beaten.
Swansea's pressure finally paid off on 28 minutes when Britton - who was at Swansea when they were relegated from the Football League in 2002 - guided a gorgeous effort into the net on 33 minutes before Dobbie drifted beyond Luke Chambers to smash a low shot beyond Camp for a fine second goal.
Forest looked a lot more sprightly in the second period with Tyson lifting a shot over the bar. Lewis McGugan then drilled a stunning shot off the top of the bar as luck continued to desert the visiting team with Swansea keeper Dorus De Vries well beaten.
Pratley could have killed off Forest when he nodded wide in space on 61 minutes, while Morgan made a superb tackle on Borini moments before Earnshaw slotted Radoslaw Majewski's pass to set up a grandstand finish.
It was not to be for Forest, who suffer more agony having lost to Blackpool 6-4 on aggregate at the same stage of the play-offs a year ago.
After nights like this when Lady Luck is nowhere to be found, manager Billy Davies must wonder whether or not he is destined to lead the former European Cup holders back to the promised land of the Premier League.