Watch a FULL FA CUP FINAL REPLAY & more via MUTV on beIN SPORTS | Sign up here | AU | NZ

Mainoo and fellow teenager Alejandro Garnacho were on target at Wembley to deny Pep Guardiola's side the double after it secured a record-breaking fourth successive Premier League title last weekend.

Although Erik ten Hag's job was reportedly on the line regardless of the result, United defended brilliantly to largely keep City at bay, despite Jeremy Doku's late strike for the Citizens.

The Red Devils subsequently held out to end a disappointing season on a high, securing a place in the UEFA Europa League next term with their first FA Cup triumph since 2016.

Mainoo, who was named in Gareth Southgate's provisional England squad for the forthcoming European championship, saluted the efforts of United's players and staff.

"[It means] absolutely everything," he said. "It's been a tough season of ups and downs. All the fans had to look forward to was this final. Last year, I was in the stands watching. I couldn't be involved.

"We knew we had to come together. The staff and the players, the preparation has been amazing. We showed that we can compete, we can come together and win on such a big stage."

Garnacho also paid tribute to his team-mate, who became the first English teenager to score in an FA Cup final since Steve MacKenzie for City against Tottenham Hotspur in 1981, while dedicating the victory to United's supporters.

"Just incredible; I say he's the best player in the squad, and he's the youngest. I'm so happy for him," the Argentinean said of Mainoo.

"[It is an] incredible feeling. Nobody believed in us, but we are together, here with these fans. An incredible moment for us, also for me and Kobbie to score the goals, but all together, we fought like it was the last day of our lives. We're so happy.

"The fans were incredible. They're always there – home games, away games, now Wembley. We won for the fans."