Anthony Martial snatched a last-gasp winner to send Louis van Gaal's Manchester United into the FA Cup final following a 2-1 victory over Everton at Wembley.
With Saturday's semi-final heading for extra-time after a 75th-minute Chris Smalling own-goal had cancelled out Marouane Fellaini's first-half strike for United, Martial was on target in injury time.
Everton, with manager Roberto Martinez under fire and out of favour with the fans, could have levelled in the 57th minute when Timothy Fosu-Mensah felled Ross Barkley but David de Gea's superb diving save denied Romelu Lukaku from the penalty spot.
United, who will face Crystal Palace in the final, had their own penalty appeal turned down nine minutes later when Fellaini's shot was blocked by Phil Jagielka's arm.
Dutchman Van Gaal has faced endless debate about his United future, with media speculation that Jose Mourinho is waiting in the wings, after crashing out of Europe and poor performances in the Premier League.
The final, with United on course to lift the trophy for the first time since 2004, would be a silver lining even if there are no guarantees that he will still be manager next season.
Elsewhere, in the Premier League, Manchester City moved up to third while Newcastle United boosted their hopes of survival by coming back from two goals down at Liverpool to draw 2-2 and secure a precious point.
On an afternoon that reaped 19 goals from four matches, last season's Player of the Year Eden Hazard finally opened his league account for the season with two in Chelsea's 4-1 win at Bournemouth.
Manchester City's bid for a top-three finish picked up extra momentum, a 4-0 demolition of Stoke City at the Etihad Stadium lifting them a point clear of fourth-placed Arsenal with 64 points from 35 matches.
Bournemouth 1-4 Chelsea
Aston Villa 2-4 Southampton
Liverpool 2-2 Newcastle United
Manchester City 4-0 Stoke City