Watch as MMA fighter's head is SPLIT OPEN by brutal knee from opponent... who claims he could see rival's BRAIN sticking out

American featherweight Justin Gonzales was fighting at PFL 6 on Friday nightGonzales' bout vs Brendan Loughnane was stopped due to his gruesome injuryREAD MORE: Paige VanZant DESTROYS her first Power Slap opponent

This is the gruesome moment an MMA fighter's head was split open by a brutal knee from his opponent on Friday night.

American featherweight Justin Gonzales was taking on Britain's Brendan Loughnane at PFL 6 in South Dakota when he suffered the sickening injury.

With just under two minutes to go in the second round of their contest, Gonzales walked straight on to a devastating knee from Loughnane after ducking down to his left.

The perfectly-timed shot opened up a deep gash on his forehead, with blood immediately seen pouring across his face as the round continued.

Before unleashing another attack, Loughnane even pointed to the cut on his rival's head in both disbelief and a plea for the fight to be ended.

This is the gruesome moment an MMA fighter's head was split open by a brutal knee

Soon after the referee put the bout on hold and invited a cage-side doctor to inspect Gonzales' cut, before he quickly concluded that he was in no position to continue.

Despite the severity of his wound, and the bloody mess it created all over his face and torso, the 33-year-old was pleading with the doctor to let him fight on.

Gonzales then had his head in his hands when Loughnane was officially awarded the victory via technical knockout.

After his hand was raised, the Manchester fighter claimed he could see Gonzales' brain sticking out of his head before the bout was waved off.

'I could see his brain,' Loughnane said. 'I could see pink brain coming through the head and I thought, "Jason [referee] do him a favor lad. This is gonna get ugly."'

Gonzales has been eliminated from the featherweight bracket of this season's PFL tournament - whereby fighters compete in a league-table system before potentially advancing to a playoff format.

American featherweight Justin Gonzales (pictured) was taking on Britain's Brendan Loughnane at PFL 6 in South Dakota when he suffered the sickening injury

Gonzales was left with a deep gash on his forehead after taking the knee to the head

Loughnane had already clinched a playoff berth before stepping into the cage on Friday night.

'I heard you're through anyway so I thought ok, let's be patient Brendan. Trying to be patient, maybe a little too patient.

'Then I started to get my timing, I landed a good calf kick. He started to come on and then the timing on that knee... I've just watched it back, it was perfect.

'So what can you say about the finish.'