DUBAI, United Arab Emirates (AP) — Australian Open champion Novak Djokovic remained unbeaten this year by routing Andreas Seppi of Italy 6-0, 6-3 as the top four seeds powered into the semifinals of the Dubai Championships on Thursday.
Defending champion Roger Federer brushed aside former world No. 3 Nikolay Davydenko 6-2, 6-2.
Djokovic will play fourth-seeded Juan Martin del Potro, who repeated his semifinal effort of last year in dispatching German qualifier Daniel Brands 6-4, 6-2. Federer will face third-seeded Tomas Berdych, who beat Russian wild card Dmitry Tursunov for the second time in five days, 6-3, 6-2.
The top-ranked Djokovic won his 11th straight match to start the year. He broke three times in the first set and once in the second that was a little more competitive. But a strong first serve in which he won 89 percent of points and a powerful forehand helped him improve his win-loss record against Seppi to 10-0.
"It was an even better performance than the first two matches, so match after match I'm elevating the level, which is good," Djokovic said. "I'm trying to do my best on the court. Tomorrow I have a big challenge, the biggest so far. Hopefully I can sustain the level from today."
Federer had also little problem with Davydenko, breaking him twice in the first set. The second set was much the same, as Federer jumped out to 4-1 when Davydenko hit a backhand into the net. Federer had two aces and an overhead smash to make it 5-1 and closed it out with a love service game.
The second-ranked Swiss has a 19-2 record against the Russian, whom he has not lost to in three years.
"I was very happy. Good match for me. I served well from the start," said Federer, who won 84 percent of his first-serve points and had a first-serve percentage of 76 percent.
"Then also I thought I had good timing on the return in particular after missing a lot of returns in the first match. I thought I was really striking it well, and then virtue of that I was getting the first strike in and then I was able to control the baseline more."
Federer said he expected a much bigger challenge from Berdych, whom he last lost to at the U.S. Open but overall has beaten the Czech in 11 of their 16 matches.
"He's got amazing power, one of the strongest guys out there on tour," Federer said. "I've struggled somewhat against him, but very often it's because his game is so big that, you know, he has a big say in the outcome of the match."
Del Potro managed to neutralize the big-serving Brands, and said his right wrist, which he injured in 2010, was not bothering him as much as it did earlier in the tournament.
"I served well today. I didn't (concede) any break points. I think I took all my chances to break his serve," Del Potro said.
Del Potro said he was satisfied his wrist was holding up, adding he will need it to be OK to tackle Djokovic.
"The good thing is I'm not getting worse. It's a good thing to be 100 percent," he said. "I know against Djokovic tomorrow I need to hit my backhand 100 percent and then see if I have a little chance to win."
Berdych also served well against Tursunov, hitting nine aces and winning 81 percent of his first-service points. He also did well to move the Russian around the court, aware that Tursunov's sore left hamstring limited his mobility.
"I know the situation. If you are in the position of playing one of the top guys and actually you don't feel well, you just have a small issue in your body, it's just a terrible match," Berdych said. "But at least you want to try. You never know what's going to happen. But once you are not really 100 percent ready, then it's tough."
Tursunov, who lost to Berdych last weekend in the Marseille semifinals, said he was considering pulling out of the Indian Wells qualifiers next week due to the injury.