LAS VEGAS -- Jameel McCline knocked Michael Grant down with the first punch of the fight, then referee Tony Weeks halted the heavyweight match 43 seconds into the bout Saturday night as the dazed Grant hobbled on an injured right ankle.

Their match was on the undercard of the WBC welterweight title bout between champion Shane Mosley and Adrian Stone, which Mosley won with a third-round knockout.

McCline, from Clinton, N.J., dropped Grant with a powerful left as the two first engaged in the center of the ring. Grant said afterward that his feet weren't set when McCline hit him and that caused the ankle injury.

Grant's injury was diagnosed as a chip fracture and his foot was placed in a cast.

Grant got up, but McCline continued to pound him until the referee stopped the bout. Grant had to be helped out of the ring, his ankle wrapped in ice.

McCline, who weighed 260 pounds, improved to 26-2-3 with his 16th knockout. The loss was just the second -- but second in a row -- for Grant, 254 pounds, from Norristown, Pa.

Grant (31-2) was knocked out in the second round by Lennox Lewis in their title bout on April 29, 2000.

McCline, who didn't turn pro until he was 25 and who had just one amateur bout, has won his last 26 fights.