Tyson Fury appeared to hit Francis Ngannou with his elbow during his controversial win on Saturday night.
The WBC heavyweight world champion controversially beat the former UFC star by split decision in Riyadh after being knocked down in the third round.
The judges scored the fight 94-95, 96-93 and 95-94 in favour of Fury, a result which was widely panned within the boxing world and beyond.
Making his professional boxing debut, Ngannou surprised the Gypsy King and even wore an illegal shot in the sixth round after Fury threw an elbow that landed clean on his face.
The Cameroonian looked momentarily startled by the hit, but immediately recovered and continued to fight. While banned in boxing, elbow shots are permitted in MMA.
Watching the fight ringside, Cristiano Ronaldo looked as surprise as Ngannou after Fury landed his elbow straight on his opponent's face.
Ronaldo was one several A-listers who attended the bout, alongside former Manchester United teammate Rio Ferdinand, Brazil star Ronaldo, ex-UFC world champion Conor McGregor and rap icons Kanye West and Eminem.
Reigning heavyweight champion Oleksandr Usyk was also in attendance, less than two months away from his undisputed heavyweight fight Fury.
Fury, the WBC heavyweight champion, is scheduled to fight the Ukrainian, who holds the three other world titles, in Saudi Arabia on December 23.
But his performance against Ngannou has cast doubts over whether the fight will go ahead as planned.
Fury himself did little to dispel doubts the fight on December 23 may be postponed.
'We'll put the biggest fight of our generation on,' he said on Sunday.
'The fight of the century for the undisputed [heavyweight] championships of the world. See you all sometime next year.
'Have a good
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