Tottenham teenager scored again to continue the club's FA Youth Cup run.
After previously dispatching Blackburn and Wolves in previous rounds, Spurs came up against a talented Manchester United side.
Spurs proved too strong, with Azzouai playing a crucial role. The summer addition from Anderlecht set up a goal for Anthony Georgiou to open the scoring, before netting himself after being assisted by captain Josh Onomah.
Georgiou added a second, with Kyle Walker-Peters setting him up, with Spurs ending the game 3-1 winners.
Azzaoui now has five goals in three matches in the competition, having bagged a stunning hat-trick against Blackburn earlier in the competition and adding another against Wolves in the previous round.
The Belgian teenager will hope for similar success when they face Nottingham Forest in the quarter-finals.
Spurs have not won the competition since 1990, although were runners-up in 1995. Chelsea are the reigning champions.