Roger Federer and Rafael Nadal progress in Qatar Open
Defending champion Roger Federer crushed Nikolay Davydenko in the first round of the Qatar Open in Doha.
The Swiss second seed's impressive 6-2 6-2 victory was in contrast to Rafael Nadal's win earlier in the day.
World number two Nadal, who has been troubled by a sore left shoulder for several weeks, had to work hard to beat Germany's Philipp Kohlschreiber.
The Spanish top seed fought back from a break down in the final set before clinching a 6-3 6-7 (2-7) 6-3 victory.
Federer romped to victory in the first set without facing a break point.
Davydenko then saved a match point on his own serve at 1-5 in the second, but that only delayed the inevitable.
The win extended Federer's winning record against the Russian to 16-2 and he will now face Slovenian qualifier Grega Zemlja in the second round.
Nadal took a 4-1 lead in the first set, the Spaniard's forehand proving too strong for his German opponent.
Kohlschreiber fought back to level in a second-set tie-break, before Nadal twice broke in the third on his way to victory to set up a tie with another German, Denis Gremelmayr.
Nadal came into the season-opening event stating his preparations had not been ideal as he attempts to adjust to using a heavier racquet.
The 25-year-old top seed had first considered switching to a heavier racquet after the US Open in September but delayed it because he felt he would not have had time to adapt because of his playing schedule.
"You can't think that everything will be perfect from the beginning," said Nadal. "But you make the change thinking it'll be better in the future.
"There's no magic, but the new racquet can help a little bit to improve my game. It's a risk I'm taking at the beginning of the season."
World number six Jo-Wilfied Tsonga also had to dig deep before beating Tunisian wildcard Malek Jaziri 7-6 (7-5) 6-7 (5-7) 6-1.