The fight was stopped at 2:46 of the eighth round in what had been an action-packed match at Staples Center in Los Angeles between the top two contenders for the belt that had been held by now-retired Lennox Lewis.
Sanders, who last year beat Klitschko's brother, Wladimir, provided a tough opponent for the Ukrainian with his left-handed counterpunching and his poise, but he suffered and slight bloody nose in the sixth round and was bleeding from a cut over the eye by the time the referee stepped in.
Klitschko's next opponent is a question mark and could be anyone from Lamon Brewster to James Toney or even Mike Tyson.
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