Rafa's foe too hip to continue

Rafael Nadal finally won another clay-court title, although not in a manner that alleviated any concerns about his recent form on his favorite surface.

The top-ranked Spaniard won his fourth Madrid Open on Sunday after Kei Nishikori was forced to withdraw with a hip injury when trailing 2-6, 6-4, 3-0 in the final.

And Nadal, who is coming off two uncharacteristic quarterfinal losses on clay, said his mental strength is still lacking just two weeks ahead of the French Open.