Federer captured his 54th career title Sunday, winning the Estoril Open when second-seeded Nikolay Davydenko retired with a left leg injury while trailing 7-6 (5), 1-2.

"I think it's the first time in my life I play a final and someone gave up," Federer said. "I guess if you put yourself in the position so many times it's going to happen eventually, but you don't hope for it."

Federer returned to his winning ways in his fifth tournament of the season. It had been eight years since Federer had needed so many events to reach a final. He won despite windy conditions and the fact that he was playing on his most challenging surface.

"It's great to win a title again, and to straightaway win my first clay-court tournament of the season gives me great confidence going into Monte Carlo," the 26-year-old Swiss star said. "I guess now, if you get better conditions, (I'll) play so much better.

"Two months ago when I didn't have enough matches and because of my sickness everything looked a little more up in the air," said Federer, who has battled mononucleosis.

Davydenko, who is ranked fourth in the world, broke Federer's serve to start the second set before pulling out of the match.

"I was running to the left and I felt some stretched muscles and (it was) painful," said Davydenko, who had received 3 minutes of medical attention at the close of the first set. "Maybe I can finish match but I don't want to lose 6-2. I have the Masters tournament coming up, so what can you do? It's really tough."

Davydenko, who fell to 0-12 against Federer, said his opponent was as tough as ever.

"He had good control, he kept the same (play) as before," the Russian said. "I don't see anything different between (the) last matches and now."

Federer added Estoril to his schedule in a bid to boost his chances of winning the French Open. The 12-time Grand Slam winner also recruited clay-court specialist Jose Higueras as coach to help win the only major championship missing from his collection.

Federer leveled his record in clay-court finals at 7-7 on a day on which cold and intermittent rain left both players reacting rather than dictating the play.

"Today was just the toughest conditions. You can't chase the line any more at all, you just try to keep the ball in play," Federer said. "It's just not easy to play aggressive tennis, it's more of a waiting game."

Maria Kirilenko beat Iveta Benesova 6-4, 6-2 to win the women's crown _ her third career title.

The second-seeded Russian broke Benesova's serve five times, helped by the Czech's five double faults. It was the third straight tournament in which Benesova lost in the final.