Wladimir Klitschko was forced to rediscover one of boxing's best weapons: His powerful right hand. With his jab ineffective, Klitschko knocked out former sparring partner Tony Thompson in the 11th round with a big right to successfully defend his heavyweight titles on Saturday. “My jab didn't work, I had to use the right - if Plan A doesn't work, try Plan B,” Klitschko said after he retained his IBF and minor WBO and IBO heavyweight titles. Klitschko (51-3, 45 knockouts) turned boos to cheers, sending the American to the canvas 1:38 into the 11th. He redeemed himself after an ugly 10th in which he pushed Thompson to the canvas and fell on him. Klitschko's ninth straight win was tougher than expected, as he had to survive a second-round head-butt that left both fighters bleeding at the right eye. “I'm still world champion, but it's about three titles now - that means everybody that fights me is extra motivated,” Klitschko said. “I haven't had a black eye for a long time, now I really look like a fighter.” His corner stemmed the cut, but his face was marked by the fight. His left eye was swollen after Thompson caught him with several good shots, especially a fifth round right hook. But Klitschko was ahead on the cards and caught Thompson in the sixth with two good rights to take control of the fight. He tired after the seventh - until he charged out in the 11th round and landed the knockout punch. That led the sellout crowd of 15,000 to chant “Klitschko, Klitschko” again. The fight came after Klitschko decisioned Sultan Ibragimov at Madison Square Garden in February, gaining him the WBO title but not winning many fans with a lackluster performance. Thompson (31-2, 19 KOs) was a WBO mandatory fight for Klitschko. He served as Klitschko's sparring partner before one of the Ukrainian's worst losses, a two-round stoppage by Corrie Sanders in 2003. Thompson's 27-fight unbeaten streak dating to 2000 was snapped. “There's a line waiting to fight me,” Klitschko said. “We will try to decide, maybe in a couple of weeks.” On the undercard, American Jonathan Banks (19-0-0, 14 knockouts) won a decision against Italy's Vincenzo Rossitto (36-5-4, 22 knockouts) to claim the vacant IBO cruiserweight title.