Kell Brook surrendered his IBF welterweight title to Errol Spence Jr. after the American produced an impressive performance to claim his first world title Saturday. Brook, who had a lot of swelling around his left eye, indicated to Foster that he couldn't continue, despite the urging of a loud, proud crowd of roughly 27,000 at Bramall Lane, a soccer stadium in Brook's hometown.
It was only the second defeat of Brook's 38-fight professional career, while Spence significantly enhanced his reputation as he improved his record to a ideal 22-0, with 19 of those wins coming inside the distance.
He broke an eye socket in the loss to Gennady Golovkin and suffered a similar injury against Spence Jr, although the extent of this latest injury is not yet known. I'm gutted I've lost my belt in front of my fans in Sheffield.
This will be the first time the 27-year-old has fought outside of America.
'It was getting worse, in the last round I had double vision and I couldn't see.
Spence Jr needed to grit his teeth and persevere through a hard sixth round when Brook turned up the heat, but the tables quickly turned.
Brook was left disappointed with a defeat in front of a partisan home crowd in Sheffield
He said: "There were many dark times and I'm dedicating this fight to previous opponent Eddie Gutknecht who is still ill".
Spence Jr. (21-0, 18 KOs) was a member of 2012 Olympic team and is regarded by many including the best boxer of this generation Floyd Mayweather as the future of boxing. Prior to the start of his professional career, he was a three-time USA national champion in the welterweight class, moving on to represent the United States at the 2012 Olympic Games in London, where he lost in the quarter-finals as a 22-year-old.
Showtime owns the broadcast rights to the fight.
Brook was unable to load up on his punches, and the fourth and fifth rounds were messy with clinches. Brook was blinking worryingly - an ominous reminder from his Golovkin fight - and he sunk to his knees before the referee saved him.
But Brook, nursing the opposite eye that needed surgery, was down again, voluntarily taking a knee. But Spence responded with a greater volume of punches, including a left and a right flush to the temple in Round 9. He stood toe-to-toe with "GGG", won a couple rounds until the power adnd size advantage became too much for Brook.