When welterweight Simon Brown, 22, of Washington, D.C., fights Shawn O'Sullivan in Toronto today, he will have several obstacles to overcome against his favored opponent.

For example, he will see Sugar Ray Leonard in O'Sullivan's corner. O'Sullivan is represented by Leonard's lawyer, Mike Trainer, and Leonard has sparred with and helped train O'Sullivan.

There also will be the pressure of appearing in his first nationally televised fight (NBC SportsWorld, 4 p.m.).

But Brown said he felt "no added pressure" about fighting before a nationwide TV audience. "I've fought in front of the cameras before on cable television ," he said, "so this is not completely new to me."

Brown also will be in the unenviable position of fighting the popular Canadian Olympic silver medalist before O'Sullivan's highly partisan hometown fans. Brown has fought in Atlantic City or Washington in every one of his 23 fights.

"The crowd may be a psychological advantage for O'Sullivan, but I'm not going to let them affect me," Brown said.

Although Brown has more professional experience than his opponent, O'Sullivan, 24, is the marquee name in this fight -- the Olympic hero who is being groomed for a title shot. Brown knows that Olympic boxers generally win early in their careers, so O'Sullivan's handlers must feel confident.

"So far, everyone seems to think that O'Sullivan's going to beat me," Brown said. "I read in a [Toronto] newspaper where someone wrote that he's going to stop me in the sixth round. I don't worry about things like that. Let them say whatever they want."

O'Sullivan, fighting mostly in his native Canada, has compiled an 11-0 record with eight knockouts, but he has not yet faced a fighter of Brown's caliber.

"O'Sullivan is taking a big step up in competition by fighting Simon," Brown's trainer, Jose Correa, said. "Frankly, I'm not impressed with him at all. I think he was a good amateur, but that's where it ends."

Of Brown's 22 victories, 16 have come by knockout. His loss came on a 12-round decision to Marlon Starling for the USBA welterweight title Nov. 12. In his last fight, March 21 at the D.C. Convention Center, he knocked out Kevin Howard in the seventh round. Howard had decked Sugar Ray Leonard in the former champion's last bout, won by Leonard May 11, 1984.

"I hear that Ray's got [O'Sullivan] moving his head a little better and helping him with his footwork, but it's not going to make a lot of difference," Correa said. "As soon as Simon hits him with a couple of good rights, he'll forget everything Ray taught him.