DOHA, Qatar -- After struggling with injuries last year, Nikolay Davydenko and Gael Monfils are playing some of their best tennis again at the Qatar Open.
Davydenko reached the quarterfinals by beating fourth-seeded Mikhail Youzhny 7-5, 6-3. He was joined by Monfils, who upset third-seed Philipp Kohlschreiber 6-4, 2-6, 6-4.
Top-seeded David Ferrer swept aside Germany qualifier Tobias Kamke 6-3, 6-2 to advance. After going down an early break in the first set, the Spaniard won five straight games on the way to winning the first set. Ferrer then saved two break points in the second to hold for 4-2 and was never challenged afterward.
Davydenko has struggled in recent years with injuries. But the Russian, who was once ranked as high as No. 3, combined a consistent first serve with aggressive play to eliminate the 25th-ranked Youzhny.
Davydenko broke his opponent to take a 6-5 lead in the first set and won when Youzhny hit a forehand into the net. Davydenko kept the momentum going into the second set, forcing Youzhny to save a break point in the first and third games. At 2-2, Davydenko won three successive games to take control.
"Really today was (a) tough match," said Davydenko, who won the tournament in Doha three years ago. "Maybe we didn't start well with so many mistakes. I know against Russians when you play in second round, it's not easy."
Ahead of the season-opening tournament, the 44th-ranked Davydenko said he was targeting a place in the top 20 this year after failing to win a tournament in 2012.
"If I really concentrate and (practice) and play, I want to see results," Davydenko said.
Monfils, who has fallen to 77th in the rankings after knee troubles forced him to cut short his 2012 season, used his powerful service game to take the lead. But in the second set, the Frenchman appeared to get frazzled by a new rule that requires players to serve in 25 seconds.
Monfils repeatedly argued with the umpire after being warned he was taking too long, and Kohlschreiber soon took a 5-1 lead in the set.
In the third set, Monfils served four of his 10 aces while Kohlschreiber started making more unforced errors. The German also missed three early chances to break Monfils.
"It's always good to have a great victory like this under your belt," Monfils said. "Physically I'm happy because I served very fast and there was no pain, so I was pleased with that. At the end of the match I was very aggressive and made the shots, so I was happy with that."
Second-seeded Richard Gasquet stormed back from a set down to beat 55th-ranked Grega Zemlja of Slovenia 6-7 (7), 6-4, 7-6 in a match that lasted nearly three hours.
Gasquet started tentatively and struggled to return Zemlja's serve. Still, he could have won the first set but failed to convert two points to seal it and then made a slew of unforced errors that cost him the tiebreaker.
The 10th-ranked Frenchman recovered in the second set. He broke Zemlja to go up 5-4 and then saved three break points to win the final game, closing it out with one of his 14 aces.
Zemlja recovered in the third set. He went up 2-0 and 5-2 only for Gasquet to win three games in a row. The match went to a tiebreaker and nerves seemed to get the best of the Slovenian. Much like Gasquet in the first tiebreaker, Zemlja couldn't keep the ball on the court.
Gasquet served well and closed out the match out with a serve and volley.
"When you're losing the first set then you have to fight," Gasquet said. "He's a very good player. I knew he was a good player, so I fight a lot and I am happy to win."