Chael Sonnen was knocked out by a flying knee from Lyoto Machida at Bellator 222.
Sonnen left his gloves in the cage and announced his retirement immediately after the fight between the two veterans at Madison Square Garden at New York.
Rory MacDonald defended his welterweight title in a unanimous decision win against Neiman Gracie. He advances to the World Grand Prix tournament final in the process.
Kyoji Horiguchi took Darrion Caldwell's bantamweight title, and Dillon Danis won by submission against Max Humphrey.
Watch full highlights from Bellator 222 in the video at the top of this page.