Mosley, who was beaten by Forrest as an amateur, was knocked down twice early on in the fight as his opponent claimed a unanimous points decision at the end of 12 rounds.

"I want a rematch," said Mosley, who lost for the first time in 39 fights. "I fought a wrong fight. It is ironic the same guy that beat me the last time, I lost to tonight."

Forrest, who beat Mosley in 1992 to win a spot on the United States' Olympic team, was happy to oblige.

"Whenever he wants a rematch, I'll give it to him," said the new champion, who was awarded the fight 118-108, 117-108 and 115-110 on the judges' scorecards.

Thirty seconds into the second round, Mosley suffered a gash on the left side of his hairline from an accidental clash of heads.

With blood streaming down his face, he was then sent to the canvas as Forrest unleashed a flurry of punches.

Mosley rose at the count of four but he was staggered by another right hand later in the round and went down again.

From then on, Forrest was in control, with Mosley acknowledging: "Vernon is an excellent fighter. He put combos together well."