Did Brock Lesnar forget he wasn't in the UFC any more?
The WWE star was taking part in the Royal Rumble pay-per-view on Monday when he hit opponent Braun Strowman with a brutal punch to the face.
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Lesnar had just received a massive knee to the head from Strowman and appeared to be pretty agitated by the harder-than-usual hit.
He then dished out a brutal jab to Strowman's jaw, stunning many fans and leaving them wondering whether it wasn't actually scripted.
While WWE is known to be more 'entertainment' than sport, it's not as fake as many believe.
Hey everybody don’t knee Brock Lesnar in the head.— Lance Storm (@LanceStorm) January 29, 2018
As it turns out, if you knee Brock Lesnar in the face, he will punch you in the head.— Jake Barnett (@barnettjake) January 29, 2018
@BrockLesnar went upside his head with a right hand. I love that!!! Get em Brock!!!— Daniel Cormier (@dc_mma) January 29, 2018
Brock Lesnar legit punched Braun Stowman in the face #royalrumble— Pro Wrestling Ultd (@pwunlimited) January 29, 2018
However we very rarely see anything as close to 'real' as Lesnar's full-blooded punch.
Lesnar last appeared in the UFC when he came out of retirement to beat Mark Hunt in July 2016.
However he returned to the WWE after failing a post-fight drug test, subsequently announcing his retirement again.