Referee Marlon Wright stopped the contest when Brook’s corner waved the towel to stop the challenger suffering more punishment after he had suffered a broken eye socket.
Brook was gutted to lose after bravely stepping up from welterweight to face the middleweight king and says he fancies the winner of next week’s light-middleweight showdown between Liam Smith and Saul ‘Canelo’ Avarez’.
“Take nothing away from Golovkin, he’s a great champion,” he said. “I would fight him again and I hope he enjoyed the fight as long as it lasted.
“I think I would be more suited at 154. Liam Smith fights Canelo next week and I’d love to fight the winner of that.
“I’m a warrior, I want to carry on. I thought I was starting to get into the fight. I knew the first rounds would be tough and then we could maybe get into it if I could come through that.
“I expected him to be a bigger puncher but in the second round he broke my eye socket… I was seeing three or four of him. But I’ll be back!”
Brook’s trainer Dominic Ingle, whose voice had gone, was booed when he tried to explain his decision to pull his man out.
Promoter Eddie Hearn paid tribute to Brook for having the guts to face Golovkin who so many other fighters were ducking him.
“Fans always want to fighters step up and fight the best and he did that,” he said. “Kell stepped up from welterweight to middleweight. He wanted the big fights and it was a hell of a fight.
“I think Kell deserves lot of respect.”