Britain's Anthony Yarde produced a brave fight against Sergey Kovalev before being knocked out in the 11th round of their WBO light-heavyweight title fight in Chelyabinsk.
The previously unbeaten Yarde had come into the contest as a big underdog against the veteran Russian, who had scored 28 stoppage wins in his 37 fights.
However, the 28-year-old Londoner showed great heart to recover from a slow start and rock Kovalev with a series of strong shots during the eight round.
Kovalev, 36, then used all of his experience to produce a response over the latter stages of the contest, flooring the Briton with a big left hand.
Yarde headed to Russia on the back of only some 18 professional fights, and while 17 had been won by knockout, the Russian's step up in class proved just too much.
Kovalev was well ahead on the cards by the end of the fourth round, but Yarde dug deep to go on the offensive during the eighth, when he looked close to putting the Russian on the canvas and silencing the partisan home crowd.
The veteran Russian, though, regrouped for the closing stages and it was then Yarde who looked out on his feet towards the end of the 10th before the stoppage soon followed.
Kovalev, making a 16th successive world title fight, is next expected to face Mexican Canelo Alvarez in a big-money showdown.