Ruslan Chagaev ended Nikolay Valuev's reign as WBA heavyweight champion with a majority points win in Stuttgart.
Chagaev outfoxed his giant opponent
Russia's Valuev, 7ft tall and 326lb, dwarfed his 6ft 1in opponent from Uzbekistan and was expected to extend his unbeaten record to 47 fights.
He was making his fourth title defence against Chagaev who extended his pro record to 23 wins and one draw.
Chagaev, 28, billed as the "White Tyson", triumphed by scores of 117-111, 115-113 and 114-114.
"I committed too many mistakes," admitted Valuev. "I did not throw enough punches and also had trouble finding my feet.
"I am respectful of my opponent and have to admit that the decision was OK. The better fighter won.
"But I will keep boxing and will be good enough to move back up the rankings in the WBA and get a new title shot soon."
Despite his 11-inch height advantage, Valuev - who weighed in at six stone heavier than Chagaev - landed few telling punches and tired considerably in the later rounds.
He looked comfortable in the first three, but was rocked by a right hook in the fourth and caught again in the fifth.
Chagaev boxed cleverly as he waited for Valuev's guard to drop and troubled him again with two clean blows in the seventh.
By the final round, the Russian giant, 33, had tired to barely a shuffle and Chagaev was ecstatic at the final bell, confident of the win.