Was that the highlight of @HaakonFoss ‘ career?? 👏 pic.twitter.com/wIOJYssbJO

Brit star Jack Mason showed off what some fans are calling the worst eye cut in MMA history after being bashed by a blistering knee during a bout Friday night.

The English welterweight suffered a first-round defeat by Hakon Foss at Cage Warriors 93 in Gothenburg, Sweden. But it was the cut above his left eye that shocked the most, and almost certainly required surgery.

A graphic video posted by fellow fighter John Maguire showed off the deep gash along his entire left eyebrow.

Mason said on Twitter after the bout: “Need to learn some knee defence.”

Stunned fans reacted with horror upon seeing the cut.

One said: “That is the worst thing I’ve ever seen in my life. It’s absolutely horrific.”

Another added: “Is that ever going to heal properly? It’s only going to keep opening up in future surely?”

One shocked user said: “This has to be the worst cut in the history of the sport. You can see pretty much everything.”

A fellow user wrote: “Most gnarly cut I’ve ever seen.”

Another said: “Holy s–t! This has to be one of the deepest cuts in MMA.”

A fellow user posted: “That is some serious cut.”

One Twitter user said after seeing the video: “I nearly vomited!”

UFC star Damien Brown said: “Goddam @JackStoneMason that’s a nasty one pal. Good to see you still getting after it.”

The defeat brings the Chelmsford-based brawler’s record to 29 wins, 17 defeats and one draw.

He was saved by referee Marc Goddard, who saw the cut and called the fight off.