Anthony Martial snatched a late winner to send Louis van Gaal's Manchester United into a potentially season-redeeming FA Cup final as the favourites following a 2-1 victory over Everton at Wembley on Saturday.
After Marouane Fellaini's first-half strike for United against his former club was cancelled out by Chris Smalling's 75th-minute own goal, Martial struck three minutes into stoppage time.
United's opponents in what will be a record-equalling 19th FA Cup final will be Watford or CrystalPalace who play on Sunday.
Everton, with manager Roberto Martinez's job looking increasingly on the line, could only rue what might have been after they missed a second-half penalty and then took the game to United.
David de Gea was as much the United hero as Martial, the Spain goalkeeper keeping out Romelu Lukaku's 57th-minute spot kick with a superb diving save after Timothy Fosu-Mensah had felled Ross Barkley.
"Everton played really well and had some chances," said De Gea.
"In one second Anthony Martial scores a goal and you win it in the last minute, it's unbelievable."
In a rollercoaster of a semi-final, with a string of missed chances keeping both sets of fans on a knife edge, United had a penalty appeal rejected in the 66th minute 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 he will still be in the job next season.
UNBRIDLED ENJOYMENT
"When you see the joy in the eyes of the players it is fantastic to see but also for the fans," said Van Gaal who has had all too few moments of such unbridled enjoyment during his tenure.
"We deserved to go to the final. I think the referee...we didn't have any fouls in our benefit. He changed the match I think."
Martial's goal, with the French forward perfectly placed to sweep in substitute Ander Herrera's through ball, unleashed the celebrations and he was also the key to United's 34th-minute opener.
He opened up the defence and provided the pass that midfielder Fellaini latched on to from six metres.
Fellaini was none too subtle about the goal celebration, making sure the Everton fans could see the name on his red shirt.
"It was a tough game. Everton asked a lot of questions but we are in a final which is most important," said the Belgian who joined United in 2013.
Everton, who were jeered at halftime, levelled thanks to Smalling's defensive clanger with the devastated England centre back sending Gerard Deulofeu's low cross into the net.
"It is a hard result to take," said Martinez who felt Everton were the better side in the second half.
"Over the 90 minutes we at least deserved the right to go into extra time. We were a little sluggish in the first half, we got the equaliser but to concede in injury time is a blow nobody deserved."
