On the road to regaining a world championship, Hilo's BJ Penn apparently ran out of gas.

Matt Hughes of Illinois defeated Penn to defend his welterweight world championship of the Ultimate Fighting Championship (UFC) organization. The main event of the UFC 63 mixed martial arts card was held last night at the Arrowhead Pond in Anaheim, Calif.

Hughes was awarded the victory when he unleashed a series of unanswered punches to Penn's face, prompting the referee to stop the contest, 3 minutes, 53 seconds into the third round.

"I knew I was in better shape than BJ," Hughes said. "I knew that I lost the first two rounds, but that meant I had three left, so I knew I had a chance."

The championship bout of the 170-pound class was scheduled for five five-minute rounds.

Penn dropped to 11-4-1, and it was the first time that he lost a fight by TKO. His previous three losses were by decision.

Hughes improved to 42-4, and avenged a loss to Penn in 2004.

Penn controlled the first two rounds, and nearly won it in the second when he applied a triangle choke on Hughes. Penn had his legs wrapped tight around Hughes' neck, but the horn sounded to end the second round.

Penn also won the first round, landing several punches to Hughes' face. Penn was also able to defend several of Hughes' takedown attempts in the first round.

"I was trying to take him down; I was very surprised that I couldn't," Hughes said. "BJ Penn is a hell of a fighter. My hat's off to him."

But Penn appeared tired in the third round. Hughes landed several punches, then took Penn to the ground. Hughes then pinned Penn's arms on the mat, and unleashed the finishing punches.

Penn defeated Hughes by choke submission to win the UFC welterweight world championship on Jan. 31, 2004. Penn was then stripped of the title after a contract dispute.

Hughes won the vacant title later in 2004, and has held it ever since.

Penn was not interviewed on the pay-per-view broadcast after last night's bout.