Roger Federer says he was pleased to see Rafael Nadal win yet another title at the French Open and defy suggestions that he might be vulnerable at the event.

"I was very happy for him because it’s tremendous what he proves on clay every year,” Federer said in Halle. “You have to raise your hat to him."

Federer, who had picked Nadal as the favorite entering the tournament despite the Spaniard's unprecedented three defeats on European clay this season, watched a portion of Nadal's victory in the final over Novak Djokovic.

"For me, it was clear before that he is the favorite," said Federer. "Now, everybody says that it was evident that he’ll win. But before it was said that he can’t play tennis anymore because he had lost on clay twice. Therefore, I think it’s nice that he proved them otherwise."