Manchester United will now have to pay Monaco £8.5m after Anthony Martial scored his 25th goal for the club against Burnley, activating a clause in his contract - via ESPN.
The French forward gave United a first half lead at Turf Moor, coolly finishing off a well-worked counter attack.
Martial was signed from Monaco in 2015 for an initial fee of £36m, but with add-ons the deal could yet surpass £50m.
Monaco looking at that 25th goal from Martial like pic.twitter.com/cBKgIiiCxF— 101 Great Goals (@101greatgoals) April 23, 2017
The 21-year-old will trigger another payment of £8m when he reaches 25 international caps for France, a total he is currently 10 short of.
Martial has scored seven goals in all competitions for United so far this season, but has found starts difficult to come by under Jose Mourinho.
The Portuguese coach recently claimed that, while he sees Martial's potential, he needs to do more to impress him to become a first team regular.
"Do I think Anthony is a player with great potential? Yes," Mourinho said - via Sky Sports. "Do I think he can play successfully for me? Yes. But he needs to give me things that I like."
Mourinho pointed to Marcus Rashford as an example of how Martial can establish himself as a regular starter.
"Since September, Rashford has not scored in the Premier League, but he was always a player I chose. He was always a player I support because he was always coming in my direction and giving me what I want, so it is about that."