Berdych is one of only three seeds left in the tournament. Eighth-seeded Ernests Gulbis of Latvia was upset by Sergiy Stakhovsky of Ukraine, 6-3, 5-7, 6-1.

In the other early match, Frenchman Richard Gasquet overcame a 5-2 deficit in the second set to beat Ukrainian qualifier Sergei Bubka 6-2, 7-5.

The seventh-ranked Berdych appeared to be on his way to an easy victory, breaking the Russian to go up 5-1 in the first set. But Davydenko won two straight games before the Czech closed out the set.

Davydenko, who had several missed volleys and errant forehands in the first set, settled down in the second. He had two sets points at 5-4, but Berdych saved the first with an ace and the second when Davydenko overhit a forehand.

Berdych failed to serve out the match after breaking for a 6-5 lead, but won two straight points from 5-5 in the tiebreaker to win.

“It was a quite big test for me,” said Berdych, who had a 1-9 record coming into the match against Davydenko. “Especially against Nikolay, it’s tough because he likes to play fast. He likes to play long rallies, and he’s very solid from the baseline.”

Davydenko was dejected after the loss, saying it was the latest blow to his confidence.

“It’s really difficult now (the) situation because I lost in the first round of the Australian Open and Rotterdam, Marseille,” he said. “For me, it’s important now to find my game.”

The 28th-ranked Gasquet looked to be making quick work of the 342nd-ranked Bubka. But he fell behind early in the second and managed to reel off five straight games to win.

He said the key moment came at 5-3 down when mishits by Bubka allowed him to close the gap to 5-4.

“You never know what can happen in the third set, so it’s good to finish the match,” Gasquet said.

It will be an all-French quarterfinal in Dubai. Gaquet will play Giles Simon, who beat qualifier Lukas Rosol of the Czech Republic 6-2, 6-3.
 
Schiavone, Li, Peer beaten at Qatar Open

In Doha, seeded players Francesca Schiavone, Li Na and Shahar Peer lost in straights sets in the second round of the Qatar Ladies Open on Wednesday.

Third-seeded Schiavone lost 7-5, 6-3 to Peng Shuai of China. Fourth-seeded Li was beaten 6-2, 6-1 by Klara Zakopalova of the Czech Republic, and eighth-seeded Peer went down 6-1, 6-0 to Marion Bartoli of France.

No. 5 Jelena Jankovic was the only seeded player to win so far, defeating Sania Mirza of India 6-0, 6-1. In another match, Daniela Hantuchova rallied to beat Vera Dushevina of Russia 4-6, 6-2, 6-4.

Peng broke Schiavone twice in each set and will play Bartoli in the quarterfinals.

“Playing against Francesca is always difficult, but I was the better player today,” Peng said. “She tested me in the first set, but I was more determined.”

Schiavone struggled with her serve, hitting five double-faults.

“I was not confident. I could not do too great,” she said. “For me to go out first round or third round is not the problem. I missed a lot of easy balls. I should take some days off perhaps, but there is no time.”
 
Fish easily advances at Delray Beach 

In Delray Beach, Florida, US second seed Mardy Fish needed only 20 minutes to reach the second round of the $442,500 ATP Delray Beach International Championships when German rival Bjorn Phau retired.

Fish led 5-0 and had dropped only six points in Tuesday's match, breaking Phau twice before the German halted the match, advancing the American into a second-round meeting with Brazil's Ricardo Mello.

South African fifth seed Kevin Anderson rallied to beat US lucky loser Donald Young 6-7 (5/7), 7-6 (7/4), 6-2 after two hours and 30 minutes, booking a second-round match against Frenchman Florent Serra.

In the night match, Juan Martin del Potro easily beat Richard Berankis 6-4, 6-1 to advance. Del Potro, of Argentina, won 79 percent of his first serves, converted 80 percent (four of five) of his break-point chances and kept his double faults to a minimum (two) in the 76-minute match.

Serbian sixth seed Janko Tipsarevic also advanced, winning an epic marathon tie-breaker and a lopsided one to eliminate Ivo Karlovic 7-6 (16/14), 7-6 (7/1) despite 18 aces from the Croatian, who lost in last year's final.

Tipsarevic will next face Slovenian qualifier Blaz Kavcic, who eliminated Colombia's Robert Farah 6-1, 6-4.

Japan's Kei Nishikori also opened with a victory, downing Argentina's Brian Dabul 6-2, 7-6 (7/5). He will next face US wild card James Blake, who ousted German seventh seed Benjamin Becker on Monday.

Colombia's Alejandro Falla advanced 6-1, 2-0 over Czech lucky loser Jan Halek, who retired 27 minutes into their first-round match.

Croatia's Ivan Dodig also reached the second round, dispatching Russian Igor Kunitsyn 6-4, 2-6, 6-3. Dodig will next face Israel's Dudi Sela, who eliminated Australian qualifier Marinko Matosevic 3-6, 6-1, 6-2.