Bruno Fernandes's early penalty was cancelled out by Suso's strike for Sevilla before United wasted a host of glorious chances and were hit by a sucker punch when Luuk De Jong turned home the winner 12 minutes from time
Sevilla carved out an opportunity to win a record-extending sixth Europa League title after coming from behind to beat Manchester United 2-1 in the semi-final on Sunday.
The Spanish side will meet in Friday's final in Cologne either Inter Milan or Shakhtar Donetsk, who play in Dusseldorf on Monday night.
Sevilla substitute Luuk De Jong scored a 78th-minute winner after Suso had cancelled out an early Bruno Fernandes penalty that put United ahead.
FULL TIME IN COLOGNE!!!! FULL TIME!!!! FULL TIME!!!!— Sevilla FC (@SevillaFC_ENG) August 16, 2020
ANOTHER FAMOUS WIN AGAINST @ManUtd AND WE'RE INTO OUR SIXTH @EuropaLeague FINAL!!!!!! YESSSSSSSSSSS!!!!!!!!!! GET INNNNN!!!!!!!!
⚽ @LuukdeJong9 #WeareSevilla #UEL pic.twitter.com/ztylS2EGnP
The Portuguese midfielder converted a ninth-minute spot-kick, United's 22nd of the season in all competitions, after Marcus Rashford was fouled by Diego Carlos as Sevilla keeper Yassine Bono saved the England forward's close-range shot.
Suso levelled in the 26th when he swept a low cross from Sergio Reguilon inside the near post.
Bono pulled off numerous saves to deny United a second, however, before Sevilla struck against the run of play.
Dutchman De Jong steered the ball past United keeper David De Gea from five metres after a Jesus Navas cross from the right left him unmarked, condemning Ole Gunnar Solskjaer's side to their third semi-final defeat of the season following the FA Cup and League Cup.