Simon Brown scored a controversial third-round technical knockout over undefeated Canadian Olympic silver medalist Shawn O'Sullivan today in their scheduled 10-round welterweight bout.

Brown, ranked fifth in the world by The Ring magazine and seventh by the International Boxing Federation, caught O'Sullivan with a devastating right midway through the third round. It dazed the hometown hero and sent him staggering to his corner, where Brown punished him with a series of lefts and rights.

With no standing eight counts in Canadian boxing, referee Fern Chretien stepped in and sent Brown to his corner. He quickly looked at Sullivan, who appeared willing and anxious to continue, but called the fight at the 2:37 mark, displeasing the partisan Toronto fans.

The victory improved Brown's record to 23-1, with 17 knockouts. O'Sullivan (11-1) suffered his first loss as a professional.

"This was just too big a step for him O'Sullivan ," said Brown's manager, Pepe Correa, who owns and operates a gym in Washington, D.C. "If that was my fighter I would have wanted them to stop the fight. If it had have gone on my fighter would have killed him. It's better to live and fight another day."

"The referee did the right thing," said Brown, who said he was looking for a match with Donald Curry. "I was hitting hard with both hands and I was just going in to finish up but he Chretien stopped it because O'Sullivan was hurt so bad."

O'Sullivan, a silver medalist at the 1984 Summer Olympics, opened the fight aggressively, scoring well in the first round. Buoyed by the support of an announced crowd of 8,000, O'Sullivan carried the fight to Brown early in the second until late in the round. Then Brown pinned O'Sullivan on the ropes and connected with a series of combinations. O'Sullivan appeared dazed and in trouble but slipped out of the danger when the bell rang to end the round.

Despite absorbing considerable punishment, O'Sullivan, 22, said he was unhurt.

"Physically I felt good, in the first and second rounds and part of the third I showed everyone I knew how to box," said O'Sullivan. "I got hit by a couple of punches and the referee decided to stop the fight. I don't understand why.

"I've been hit harder but that was nothing that merited stopping the fight. The first blow the overhand right midway through the third was the most damaging, the next one was a slap and the third a glancing blow. All my faculties were there."

Brown, 24, a native of Jamaica who lives in Washington, said after the fight: "I'm feeling pretty good now. When I first got up here, people said I had to knock him out to win. I went in there with the idea of going in there and trying to win, not thinking about the knockout.

"When I looked up I saw the crowd. I've never been in that situation before, where it seemed everybody was cheering for my opponent. I just said to myself, 'Concentrate on my opponent, just go in there and go to work.' "

Brown said the victory was his "biggest win ever" and was "a great opportunity, on national TV, to show the fans what Simon Brown is about."

Brown weighed in this morning at 148 pounds; O'Sullivan tipped the scales at 149.