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.
1. Manchester United player ratings
How did Manchester United's players fare in Sunday's FA Cup quarter final against Liverpool.
2. Andre Onana - 6
Couldn't really do too much about any of the goals and made some routine saves.
3. Diogo Dalot - 6
Not the only player in the United side that started well but gradually faded as the game wore on.
4. Aaron Wan-Bissaka - 7
Stuck to his task reasonably well against Salah and tried his best to get forwards and support the attack.