COPENHAGEN, Denmark -- Joe Calzaghe stopped Will McIntyre in the fourth round Saturday to successfully defend his WBO super middleweight title.

Calzaghe, of Wales, improved to 32-0 with 27 KOs. McIntyre, of Bogalusa, La., dropped to 29-3.

Calzaghe controlled the fight from the opening bell and almost put McIntyre down in the first round, hitting the American almost at will. After McIntyre rallied slightly in the second, Calzaghe took charge again in the third and knocked down McIntyre at the end of the round.

Calzaghe sent McIntyre to the mat again in the fourth, and the fight was stopped 35 seconds into the round.

Both fighters weighed in at 167½ pounds.

Calzaghe's victory could put him in line for a high-profile unification fight in the United States, where he has never fought.

"Right from the start I knew I had him in trouble," Calzaghe said. "My hand speed was too much for McIntyre."

The loser agreed.

"He was a lot faster than I thought he would be. ... I wanted to continue but the referee did the right thing," McIntyre said.

"I give him a lot of credit for having the courage to fight me," Calzaghe said. "A lot of opponents pulled out. I want Roy Jones. I want Bernard Hopkins."

The fight was on the undercard of Mike Tyson's bout against Brian Nielsen.

Also on the undercard, heavyweight Ray Mercer knocked out Brian Scott in the second round. Mercer's next fight is expected to be against WBO champion Wladimir Klitschko.

In other fights, welterweight Carlos Baldomir won a 12-round unanimous decision against Hasan Al, bantamweight Johnny Bredahl outpointed Evangelo de Jesus Perez over six rounds, and lightweight Soren Bladt took a six-round decision against Brad Timm.

Heavyweight Ray Phillips quit with an injury in the first round of his fight against Rune Lillebuen, super middleweight Mikkel Kessler outpointed David Mendez over six rounds, and welterweight Thomas Damgaard stopped Freddy Italo Rojas in the third round.