Roger Federer recovered from a set down in Estoril to beat world number 104 Denis Gremelmayr 2-6 7-5 6-1 and reach his first final of the year.

The out-of-form world number one struggled to counter the unseeded German's powerful baseline game before pulling clear with a series of aces.

"I had to work hard but at least there was no rain today," Federer said of the challenging, gusty conditions.

He faces Nikolay Davydenko in Sunday's final.

Federer, 26, said of his win on Saturday: "People have been saying that I'm struggling, that I lost five games in the quarter-finals.

"I guess that's a good problem to have - it's bigger news when I lose than when I win."

As red dust blew into both player's faces at times, Federer struggled to adapt in the first set.

But he settled down, breaking four times in the final two sets to clinch his path to the final.