JAMIE Cox suffered the first defeat of his professional career as his bid to become a world champion was ended by George Groves in tonight's World Boxing Super Series quarter final at Wembley's SSE Arena tonight.

The Swindon southpaw was caught with a big right to the rib cage from dfeending champion Groves, crumbling to the canvas in agony and unable to beat referee Steve Gray’s count in the fourth round.

After a cagey start to the opening round, Groves and Cox had a tear-up, but it was the WBA Super super-middleweight champion who was having the greater success.

However, Cox came back in the second, backing the champion into the corner and unleashing a barrage of punches that troubled Groves.

The former Walcot amateur had some early success in the third round but Cox was leaving himself too open and Groves was again finding the target.

And the fight was brought to a halt after 1.42 of the fourth round when Groves landed a thumping body shot that sent Cox to the canvas.

After the fight, Cox told ITV Box Office said: “He was a very good champion, I made a mistake and he made me pay.

“It was a great fight until then. I thought I was coming into the fight and he landed a good shot to the body.

“I expected him to be stronger, he was a very good boxer, but I could handle his power, but he placed a shot very well and credit to George.

“I’m an aggressive fighter and I think that George made me over-commit on the aggressiveness.”