On Saturday night at the O2 Arena in Hamburg Germany, Wladimir Klitschko (63-3-0, 53 knockouts) pulverized Kubrat Pulev (20-1, 11 KOs), knocking him out in the fifth round with a lethal left hook. Klitschko’s victory marked his 17th consecutive title defense. He is third in line behind Joe Louis (25) and Larry Holmes (20). At 38, Klitschko seems unbeatable. Eight years into his reign, he has dominated his division more than any other active champion today. He holds the IBF, WBA, and WBO titles, but remains one belt away from realizing his most immediate goal, unifying the heavyweight crown.