Nineteen-year-old Garnacho fired United ahead after 30 minutes before Mainoo, also 19, finished a magnificent move with United’s second goal nine minutes later, with the pair becoming the first pair of teenagers to score in an FA Cup final.
Substitute Jeremy Doku pulled a goal back for Man City three minutes from time, but it was not enough as Premier League champions City fell short in their quest to become the first club to win back-to-back League and FA Cup Doubles.
Defeat ended Man City’s 35-match unbeaten run, while Erik ten Hag became the first manager to beat Pep Guardiola’s side in a major domestic cup final.
How the match unfolded
Newly crowned champions Man City made three changes from the side that started their title-clinching final match of the Premier League season last Sunday.
John Stones, Nathan Ake and Mateo Kovacic came in, with Ruben Dias, Manuel Akanji and Doku dropping to the bench.
For Man Utd, Marcus Rashford and Raphael Varane both returned to the starting XI, while in Garnacho and Mainoo, they became the first side since Millwall in 2004 (against United) to start at least two teenagers in an FA Cup final.
Man City had a penalty appeal waved away in the opening minute when Erling Haaland went down under a challenge from Lisandro Martinez as he tried to connect with Bernardo Silva‘s ball into the six-yard box.
But it was Garnacho who silenced City’s fans with United’s opening goal after 30 minutes, capitalising on a defensive mix-up between Stefan Ortega and Josko Gvardiol to steal in and tap into an empty net from close range.
Garnacho became the first Argentinian to score in an FA Cup final since Ricardo Villa for Tottenham Hotspur against Man City in 1981.
It was also only the fourth goal that City had conceded in the FA Cup in two years, and nine minutes later it became the fifth, when Rashford’s superb crossfield ball picked out Garnacho, he fed Bruno Fernandes and from the captain’s sublime lay-off, Mainoo swept home to make it 2-0.
In scoring, 19-year-old Mainoo became the first English teenager to net in an FA Cup final since Steve MacKenzie for Man City in that same match against Spurs.
Guardiola responded by bringing on Akanji and Doku for Kovacic and Ake at the start of the second half, sparking a positive City response, with 2023/24 Golden Boot winner Haaland crashing a 55th-minute shot against the crossbar.
Man Utd goalkeeper Andre Onana was called into action on the hour, superbly diving to keep out Kyle Walker‘s long-range effort.
Julian Alvarez dragged his shot wide of the upright in a one-on-one with Onana soon after from Phil Foden‘s pass as City piled on the pressure.
Onana denied Walker again with a brilliant low save before Doku pulled a goal back on 87 minutes, beating the ‘keeper at his near post, to set up a frantic finale.
But United, who finished the Premier League season 31 points behind their bitter rivals, dug in and held firm for a famous victory – and their first FA Cup final success in eight years.
In doing so, they ended Rodri‘s remarkable record of going 74 matches without defeat in all competitions for Man City.
