Robert Stieglitz (36-2, 22 KOs) defeated super middleweight contender Karoly Balzsay (21-1, 15 KOs) when the favored defending beltholder was unable to continue after the 10th round of their WBO 168-pound titlebout that took place in Balzsay's native Budapest, Hungary on Saturday.

Balzsay, who was attempting to make the second defense of the title he won from Denis Inkin in January, fought on even terms with Stieglitz in the early and middle rounds of the action bout but the Russian-born German wore down the Hungarian titleholder late in the fight.

Stieglitz repeatedly stunned and wobbled the fast-fading Balzsay in rounds nine and 10, prompting the beltholder's trainer Fritz Sdunek to prevent him coming out for the 11th round.

The upset victory was Stieglitz's fifth consecutive win since he suffered an eighth-round stoppage loss to top contender Librado Andrade last March. Stieglitz's only other loss was a third-round TKO to Alejandro Berrio in a 2007 title bout.