IBF/IBO/WBC/WBA middleweight world champion Gennady Golovkin (36-0, 33KOs) thanked Kell Brook (36-1, 25KOs) for indulging his desire for a crazy street fight at London’s O2 Arena.

Golovkin, who now has 33 stoppage wins in an unblemished 36-fight record, handed welterweight Brook his first professional loss over five brutal and thrilling rounds on the banks of the Thames last night.

The 34-year-old Kazakh superstar had his WBC, IBO and IBF belts on the line and hurt Brook with a shuddering left hook in the opening session before the 147-pound IBF ruler sensationally elected to fight fire with fire.

Ultimately, Golovkin’s fearsome punching power and suffocating ring generalship sapped Brook’s resistance and the challenger’s face was battered and bloodied when his corner threw in the towel after one minute and 57 seconds of the fifth.

Brook was unable to attend the post-fight news conference as he went to hospital with a broken right eye socket, leaving Golovkin to hold court — marvelling at his vanquished boxing foe’s skill and bravery but stating the jump in weight was too big a gap for him to bridge.

But Brook may be rewarded for his efforts, because in the aftermath HBO Sports President Peter Nelson approached Eddie Hearn of Matchroom Sport to express his interest in Brook.

“Peter Nelson has already come up to me and said: ‘We need to talk about Kell Brook’,” said Hearn. “That was part of the plan: to broaden the brand. So actually, it was a very smart move [to move up to 160 for Golovkin].”