WARNING: This article includes images that may cause distress

A shockingly gruesome injury has forced a bare knuckle boxer to retire after he was brutally

knocked out on Sunday morning (AEST).

Connor Tierney was beaten by Rico Franco at BKFC 90 as the referee waved off the fight in the second round when The Brumtown Bomber was dropped by a thunderous right hand.

That came after an accidental head clash severely impacted Tierney earlier in the contest.

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And it was the act of the heads coming together which appeared to cause the devastating blows to the fighter’s mouth as Tierney shared the extent of his horrific injuries on social media.

His teeth were clearly disfigured and his lip covered in blood — while he also posted an X-ray showing his jaw snapped into two pieces.

Alongside the shocking images of his mouth, Tierney, 31, also confirmed his retirement from the sport.

The fighter, who is also a chartered surveyor, said: “Bare-knuckle has been some journey but this injury is it for me.

“I’ve had a fantastic career, I really have. I hope I’ve inspired as many people as I aimed to.

“Thank you to everyone who has shown support over the years.

“One thing I’m proud of is the legacy I’ll leave behind when it comes to support and atmosphere.

“£105,000 tickets done for last night, £60,000 for the Danny Christie fight last year, you won’t get many homegrown fighters do that amount that haven’t come off the back of a big boxing or MMA background, and even then I would have outsold a vast majority of them big time fighters!

“Like I always said, I wanted to be the Ricky Hatton of it, the people’s champion. I got to do that so I’m trying [to be] grateful.”

Tierney retires with a record of nine wins and three losses.