Who defeated Randy Couture for the UFC heavyweight title at UFC 91?

Brock Lesnar defeated Randy Couture for the UFC heavyweight title at UFC 91. Lesnar stopped Couture by second-round technical knockout on November 15, 2008, in Las Vegas.

The matchup paired the experienced champion with one of the UFC’s most physically imposing newcomers. Couture had returned from a lengthy absence and reclaimed the heavyweight championship, while Lesnar had only a few professional mixed martial arts bouts but possessed exceptional size, wrestling ability, and athletic power.

Lesnar hurt Couture with punches against the fence before finishing with ground strikes at 3:07 of round two. The victory made him UFC heavyweight champion and established him as a major force in the division.

This result is sometimes confused with Frank Mir, who had previously submitted Lesnar at UFC 81 and later fought him again. Shane Carwin and Cain Velasquez challenged Lesnar afterward, but neither defeated Couture at UFC 91.