WBA, IBF and WBO heavyweight champion Wladimir Klitschko ran his unbeaten streak to 18 consecutive fights with a sixth-round TKO of Francesco Pianeta on Saturday.
Klitschko (60-3), who hasn't lost since a fifth-round TKO by Lamon Brewster in 2004, knocked Pianeta down with a right hand in the fourth round and floored the Italian challenger with a left in the fifth before the fight was halted at 2:52 of the sixth.
The 37-year-old Klitschko, who remained perfect in 15 lifetime bouts in Germany, has held the IBF belt since 2006 and claimed the WBO crown two years later. He claimed the WBA title with a unanimous decision over Englishman David Haye in 2011.
Pianeta (29-1-1), a cancer survivor appearing in a world title fight for the first time in his career, suffered his first-ever professional defeat.