Alejandro Garnacho's family were seen crying tears of joy in the stands at Old Trafford as the 17-year-old forward made his debut for Manchester United.
The Madrid-born forward - who last month was called up to the senior Argentina squad - was brought on for Anthony Elanga in the first minute of stoppage time of their 1-1 draw against Chelsea on Thursday.
United fans have been calling for Garnacho's first-team debut ever since he scored in the 3-0 against Wolves in last month's FA Youth Cup semi-final.
And Garnacho was finally handed his eagerly-anticipated first-team debut for United by Ralf Rangnick, which drew an emotional reaction from his family who had been given some of the best seats in the house.
As Garnacho came on, his family stood up and applauded the moment in an emotional scene. His mum then records his first time stepping on to the United pitch as a first-team player with her mobile.
His father cries as his son comes on, but it is the forward's brother who most notably struggled to hold back tears just seconds after Garnacho's name was read out by the stadium announcer.
Reports then suggested injured United captain Harry Maguire and United chief Richard Arnold went over to Garnacho's family at the final whistle to congratulate them on his debut.
Posting on Instagram after the game, Garnacho insisted he has been 'dreaming' of the moment he got to experience last night since he was four years old.
'Incredible moment making my debut at 17 years old for Manchester United in the Premier League at the Theatre of Dreams,' he wrote.
'I can't put into words what I'm feeling right now, I've been dreaming of this moment since I was 4 years old.
'I would like to thank everyone at the club for giving me this opportunity, my family for always being there for me, my friends and all the fans for their constant support.
'The hard work continues in order to have more nights like these. And remember guys, Dreams really do come true.'
The Red Devils fended off interest from Real Madrid and Borussia Dortmund to sign Garnacho from Atletico Madrid in 2020 and he has gone on to star at U18, U19 and U23 level down the left-hand side of the attack.
This season, however, has seen him reach another level, helping the U18s reach the club's first FA Youth Cup final - which they will contest against either Chelsea or Nottingham Forest next month - since their 2011 win against Sheffield United.
The 17-year-old has been rather prolific in the competition, netting five times in four games to go with three assists in their run to the final, which has included wins against Scunthrope, Reading, Everton, Leicester and Wolves.
This term, across all competitions - which include the Premier League 2, UEFA Youth League and the U18s Premier League - he has netted 12 goals combined with six assists in 31 games.
And it was in a brilliant solo goal against the Toffees U18s shown on MUTV where he paid tribute to his idol, Man United and Real Madrid legend Cristiano Ronaldo by performing the five-time Ballon d'Or winner's trademark 'Siu' celebration.
Then last month, he linked up with and had a photo with the most iconic name in Argentina's 40-man provisional squad called up by Lionel Scaloni last month in Lionel Messi.
The United youngster was clearly left star struck, sharing an image with Messi on Wednesday night on Instagram, calling the forward his 'idol' in the post.