Role reversal suits Rooney
Entering the twilight of his illustrious career, Wayne Rooney has accepted that his declining pace means a deeper position as a midfield playmaker is a better use of his gifts than his former role at the heart of United's forward line.
The United captain suggested he could make the transition work, as he took up good positions and used the ball effectively.
His best moment came when he was pushed forward as United chased an equaliser, with a brilliant, determined run past a host of Palace defenders ending with the fine cross that produced Juan Mata's 81st-minute leveller.
Super-sub sinks Palace
Jesse Lingard had found himself in limbo for much of the season as the young United forward lurched between occasional starts and long spells on the bench.
The 23-year-old, a product of the club's youth academy, had been overshadowed by Marcus Rashford's emergence, but he has an eye for goal, as he showed when he made the most of his substitute appearance with the blistering 110th-minute volley that won the Cup for United.
Injury blow for Rashford
Rashford has emerged as one of the few bright spots in a troubled campaign for United and the 18-year-old forward underlined his vast potential with a mature display against Palace before cruelly seeing his afternoon curtailed by injury.
Having burst into the United team due to injuries just a few months ago, Rashford had seized his opportunity to such an extent that he is in contention for a place in England's final 23-man squad for Euro 2016. On this evidence he should go to France as his pace was a constant menace for the Palace defence.
Initial reports claimed his injury, suffered in a second-half tackle with Yohan Cabaye, was not too serious, but he now faces a nervous wait to see if he recovers in time.
Puncheon makes his mark
A day that started with Jason Puncheon at his lowest ebb after being left on the bench by Palace manager Alan Pardew eventually produced a moment of ecstasy for the Eagles midfielder.
Pardew had promised Puncheon that he could still be a hero despite the selection snub.
Born in Croydon just a few miles from Selhurst Park, the 29-year-old was on the verge of becoming a Palace legend when he came on to put the south Londoners ahead in the 78th minute with a powerful near-post strike.