Onetime Sox slugger Jose Canseco was the one getting slugged Saturday. The disgraced former major leaguer was knocked down to the mat by former Philadelphia Eagle Vai Sikahema in the first round of a celebrity boxing match in Atlantic City. The 5-foot-9 Sikahema, who's 45 and works these days as a sportscaster, swarmed the 44-year-old Canseco, who stands 6-foot-4, as soon as the opening bell sounded. He knocked the admitted steroid user down twice before the fight was stopped. The crowd stood and roared. "When you step inside the square circle," Sikahema said, "don't ever think that your size is going to matter because in Philadelphia, we will chop you down." Sikahema donated $5,000 of his winnings to the family of slain Philly cop Stephen Liczbinski, who was killed in May while responding to a bank robbery. The fans booed as Canseco entered the ring. He inflamed the crowd by pointing toward Sikahema's corner and making a throat-slashing gesture.