Evander Holyfield appeared to do more than enough to defeat 7-foot Nikolai Valuev on Saturday in their heavyweight bout, but the three judges in Zurich saw otherwise.
Valuev won by a majority decision over Holyfield, 46, despite not landing anything of note until the second half of the 12-round fight. The scores were 116-112, 115-113, 114-114.
The Russian improved to 50-1 (35 knockouts). Holyfield dropped to 42-10-2 (27 KOs).
"Of course I am disappointed," said Holyfield. "I thought I had done enough to get the win. Now I have to go home and think about my future."
The fighters were vying for a portion of the World Boxing Association belt due to the long-term injury of titleholder Ruslan Chagaev, who won by decision over the previously unbeaten Valuev 18 months ago.
The winner is expected to face the undefeated Chagaev in 2009.
Holyfield hadn't fought since a comprehensive decision loss 14 months ago to Sultan Ibragimov and came into the bout 6-6-2 in his last 14 fights.
Many in boxing have urged Holyfield to retire but he needed only a little bit of his former greatness to confound the Russian.
Valuev weighed 310 pounds, 96 more than the American. The Russian called Holyfield a "legend" in the run-up to the fight and he boxed like he was in awe.
He was simply too slow to time Holyfield, who in the early rounds would land a shot or two and be well out of harm's way before the oafish Valuev could pull the trigger.
Valuev enjoyed modest success in the middle rounds when Holyfield kept moving but neglected to throw as many punches.
Holyfield landed the best combinations of the fight in the 10th round and clearly took the 11th as well. Valuev, 35, finished strong in the last round as Holyfield tired.
"He made me work very hard for the win," said Valuev. "Holyfield was unbelievable with his speed. The fight was fought at a great tempo for the whole 12 rounds."
Holyfield first won the heavyweight title in 1990 with a knockout over Buster Douglas, and regained portions of the title in 1993, 1996 and 2000.
George Foreman, a former Holyfield opponent, was 45 when he won the linear heavyweight title with a shocking one-punch knockout over Michael Moorer in 1994.