Martial made it 1-0 for United in the first half, and it means they will now have to stump up another fee to Monaco.

Louis van Gaal signed Martial in 2015 from Monaco for an initial £36 million but the fee could surpass £50 million in future add-ons. Martial's goal on Sunday was his 25th for Manchester United -- the landmark required to trigger the extra payment. 

Martial, 21, also has 15 national caps for the France senior side, 10 short of a total that would require United to come up with an £8 million payment.