Amad Diallo wrote his name into Manchester United folklore after the young winger netted the winning goal to help his side edge of arch rivals Liverpool in a rollercoaster of an FA Cup tie.
After both sides swapped chances inside the opening stages it was the Red Devils that grabbed the first goal of the game with ten minutes on the clock as Scott McTominay tapped home from close range after Alejandro Garnacho brought a save out of visitors keeper Coaimhin Kelleher.
After Bruno Fernandes and McTominay both came close to extending the lead, Liverpool thought they had grabbed an equaliser seven minutes before half-time when an offside decision against Mo Salah led to a Waturo Endo goal being ruled out.
However, there was no denying the Reds just before half-time when a deflected effort from Alexis Mac Allister and a goal from the ever dangerous Salah ensured it was Jurgen Klopp's side that took a narrow lead into the interval.
The momentum gained by their quickfire double ensured Liverpool enjoyed the better of the second-half - but there was little they could do when Ten Hag reaped the rewards of a number of changes as Antony came off the bench to beat Kelleher with just four minutes remaining.
Marcus Rashford could and should have secured a win in normal time for United when he somehow missed a golden chance in the final seconds - although he made amended in extra-time as he cancelled out a Harvey Elliott goal that had put the visitors back in front. That would set the scene for Amad to fire home the winning goal to send his side into the semi-finals and ensure United supporters have a new hero.
After a remarkable day at Old Trafford, ManchesterWorld hands out our United player ratings.
13. SUB: Harry Maguire (on for Wan-Bissaka 79) - 6
A solid enough display from the England centre-back as he seemed to bring some control to the United backline and looked a threat in attack too. | Getty Images
14. SUB: Antony (on for Hojlund 79) - 7
Took his goal brilliantly with a neat turn and finish. Really did swing the momentum of the game back in United's favour for a short time. | Manchester United via Getty Imag
15. Christian Eriksen (on for Mainoo 80) - 5
Produced some neat passes without really threatening. | Getty Images
16. SUB: Amad Diallo (on for Varane 86) - 8
Was a lively presence following his introduction and the eventual match-winner. Would not be a shock to see Amad receive more game-time throughout the remainder of the season. | AFP via Getty Images