Felix Sturm retained his WBA middleweight title Friday when Sebastian Zbik's corner threw in the towel after nine rounds of their scheduled 12-round bout.

Sturm (37-2-2) was coming off a 12-round draw with Martin Murray in December and remained unbeaten since 2006 with the TKO of his fellow German.

Zbik (30-2) remained winless in two title fights and lost for the first time in 26 bouts in his home country.