West Philadelphia's Steve Cunnigham trotted to the center of the ring as the bell sounded Saturday afternoon and threw his arms in the air.
The heavyweight boxer's opponent, Tomasz Adamek, retreated to his corner at the Sands Casino in Bethlehem, Pa. and met his trainer.
But Cunningham's jubilation turned to frustration as ring announcer Michael Buffer announced that the 12-round fight was ruled a split-decision draw.
Buffer then corrected himself and announced the fight was a split decision in favor of Adamek.
The decision marked the first loss for Cunningham (25-5) since moving to the heavyweight class in September. Adamek improved to 48-2 and captured the vacant IBF North American title.
In 2008, Adamek topped Cunningham on a split decision while both were cruiserweights.
In Saturday's 12th and final round, both fighters appeared exhausted as they navigated the ring and exchanged a flurry of punches.
Cunningham's mouth was bloddied as a result of Adamek's inadvertent 10th-round headbutt. Earlier in the 10th round, Cunningham lured Adamek to his left side before targeting with him a strong right to the face.
In the sixth round, the 36-year-old Cunningham connected with a strong counter-right to his opponent's chest, which appeared to knock the wind out of Adamek.