On a night where mixed martial arts fans watched UFC 238 in Chicago set a new record for the most significant strikes landed at one event — boxing wasn’t exactly violence-free.

Gennady Golovkin resumed normal service after a controversial defeat against Canelo Alvarez with a clinical fourth-round knockout of Steve Rolls.

But the nastiest KO during the Saturday night fights in the US came in Reno.

ESPN broadcast a card in the Nevada city headlined by undefeated featherweight Oscar Valdez’s WBO title win against Jason Sanchez.

But the real action was on the final bout of the undercard where light heavyweights Michael Seals and Christopher Brooker squared off.

Christopher Brooker folded up like a deckchair.

Christopher Brooker folded up like a deckchair.Source: Twitter

Michael Seals had an easy night.

Michael Seals had an easy night.Source: Twitter

The brawl was all over in the second round as Brooker went catatonic after a shot that appeared to only graze his head.

Fight fans were watching the blow on repeat in an attempt to figure out what caused the Philadelphia battler to fold backwards through the ropes with his right leg bend and his neck unable to support his head.

One potential explanation was the damage being done by Seals’ left knee, rather than the punch, as Brooker’s head appeared to make contact with hit.

Either way it was stunning footage.