Gennady Golovkin defended his WBA middleweight title with an 11th-round stoppage of Britain's Martin Murray in Monte Carlo.
Murray, 32, was twice knocked down by body shots in the fourth but showed bravery to take the undefeated champion past 10 rounds for the first time.
The Kazakh also floored Murray in the 10th and the referee stopped it with 50 seconds left in the penultimate round.
Golovkin, also 32, now has 29 knockouts from 32 professional fights.
His knockout percentage was already the highest of any world middleweight champion in history.
It is the third time Murray has come up short challenging for a world title - he was unlucky only to draw with Germany's Felix Sturm in 2011 and was narrowly outpointed by Argentina's Sergio Martinez in 2013.
But on this occasion there could be no complaints, with Golovkin pushing the challenger on the back foot from the opening exchanges and never letting up.
|Martin Murray, post-fight:|
|"Gennady Golovkin is strong and tough. I couldn't have done any more - I gave it my all and that's the best I can do. It wasn't good enough tonight and I'm absolutely gutted, but he's a great fighter and a great champion. There was not much more that I could have done."|
|Read the round-by-round report|
Murray actually looked comfortable in the early rounds, despite spending a lot of time on the ropes, until the champion landed with a chopping right hand at the end of round three.
Having softened Murray up, Golovkin had him down with twice in round four courtesy of right hands to the body and the challenger did well to survive.
Murray rallied in the middle rounds, landing with some smart shots on the inside and at least keeping Golovkin honest.
But an overhand right floored Murray again towards the end of the 10th and with the challenger reeling on the ropes in the following round, Luis Pabon stepped in.
Golovkin has now won 19 fights in a row inside the distance and with little left to prove at 160lb, he might choose to step up to super-middleweight.
Puerto Rican great Miguel Cotto is the WBC champion at 160lb but, unsurprisingly, does not seem interested in facing the devastating Golovkin.
Britain's Carl Froch, the WBA champion, is unlikely to want to face Golovkin in his final fight this summer but American Andre Ward could be tempted.
Ward is unbeaten in 27 professional contests but has not fought since 2013 because of a dispute with his promoter, which has now been resolved.
Murray, who falls to 29 wins and two defeats from 32 fights, still has options at middleweight and will surely fight for a world title for a fourth time.