Gennady Golovkin retained his WBC and IBF middleweight belts with a fifth-round stoppage of Britain's Kell Brook in London on Saturday.
Kazakh Golovkin took his career record to 36 victories from 36 fights but he was shaken early by welterweight world champion Brook who had moved up two weights to challenge for the title.
Previously unbeaten Brook produced a scintillating second round, rocking Golovkin with a vicious left uppercut, and was standing his ground against a marauding champion as the O2 Arena crowd in London roared its approval.
However, with his right eye closing, Brook began to take some serious punishment in the fourth round and again in the fifth when trainer Dominic Ingle threw in the towel to prevent his man suffering serious injury.
