Manchester United booked an FA Youth Cup final against neighbours Manchester City after beating Crystal Palace 2-1.
Chido Obi scored the winner in extra-time after JJ Gabriel's second-half goal was cancelled out minutes later during a tightly contested semi-final at Old Trafford.
Darren Fletcher's side will now face Manchester City in early May, with the date and the venue - likely to be the Etihad Stadium or the Joie Stadium - still to be confirmed.
A cagey game was finally unlocked on the 77th minute after an impressive cameo off the bench by Samuel Lusale. He found Obi, who put in the 15-year-old Gabriel after some impressive hold-up play.
Gabriel then drove towards goal before producing a sublime chipped finish over the Palace goalkeeper, but the lead was short-lived.
Just minutes later, United keeper Cameron Byrne-Hughes fumbled the ball after trying to catch it in the air, with Palace attacker Raihaan Anderson eventually making him pay.
United lost their way after the equaliser and Palace were firmly on top as the game went into extra-time.
But in the 115th minute, a defence-splitting ball was delivered by James Overy from the right-hand side and Obi met it, cooly dribbled past the goalkeeper and finished into an empty net.
Analysis from Your Site News' Dan Khan:
First-team coach Tavis Binnion, director of football Jason Wilcox and academy director Stephen Torpey were all in attendance at Old Trafford to see Carrington's best get through to the FA Youth Cup final.
JJ Gabriel will take the headlines after a moment of magic put his side into the lead. His quality continues to shine and build up a reputation that is almost unprecedented in decades for a young player coming through Carrington.
Obi had a rollercoaster evening. He missed two big chances in the game but then set up Gabriel brilliantly for United's opener, before his winner showed his potential if he develops his all-round game further. The composure to dribble past the keeper and finish in the last minutes of extra-time was sublime.
With Wilcox and co watching, could Obi and Gabriel play themselves into the first-team's pre-season plans? There will be spaces up for grabs with the World Cup taking centre stage this summer.
That's in the future but for now, United are in the final once again of the Youth Cup.
It is a competition they have won a record 11 times, the last being in 2022 when Kobbie Mainoo starred.
Manchester City await them in a mouth-watering final next month.
Man Utd: Cameron Byrne-Hughes; Yuel Helafu, Albert Mills, Daniel Armer (c), Godwill Kukonki; Rafe McCormack, Jim Thwaites; Junior Brown, JJ Gabriel, Noah Ajayi, Chido Obi.
Crystal Palace: Lucca Benetton, Jacob Fasida, Dean Benamar, Charlie Walker-Smith, Sean Somade; Chuks Okoli (c), Joel Drakes-Thomas, Euan Danaher, Benji Casey, Raihaan Anderson, David Angibeaud.
Attendance: 3,189
