DOHA (AP) ― Rafael Nadal struggled past Philipp Kohlschreiber while defending Qatar Open champion Roger Federer routed Nikolay Davydenko in their season openers on Tuesday.

The second-ranked Nadal overcame Kohlschreiber of Germany 6-3, 6-7 (2), 6-3 in a match that lasted 2 1/2 hours. Federer, who lost badly to Nadal and No. 1-ranked Novak Djokovic over the weekend at an exhibition tournament in Abu Dhabi, showed he had shaken off the rust by overwhelming the injury-plagued Davydenko 6-2, 6-2 in just 54 minutes.

Also, No. 6 Jo-Wilfried Tsonga beat Tunisian wild card Malek Jaziri 7-6 (5), 6-7 (5), 6-1 and fourth-ranked Gael Monfils defeated Rui Machado of Portugal 7-5, 6-3.

Nadal, who has struggled with a sore left shoulder since the end of last season, started well and looked headed for a routine victory. But the 43rd-ranked Kohlschreiber stepped up his net play in the second set and jumped to a 4-1 lead on his way to evening the match. Kohlschreiber went up a break in the third but Nadal broke back and took control from there.

Nadal ripped a cross-court forehand past Kohlschreiber to go up 2-1 and then broke for 3-1. Helped by an improving serve and able to win most of the big rallies, Nadal jumped to 5-2 and closed the match with an acrobatic overhead smash and then a vicious cross-court forehand that Kohlschreiber couldn’t reach.

“In general, for me, (this) was a really positive match,” Nadal said. “I think I played a very good first set. The only moment that I didn’t play well was the beginning of the second and after the tiebreak. For the rest, I think I played a very solid match.”

Nadal admitted Kohlschreiber was a tough opening draw, since he often plays much better than his ranking would indicate.