Viktor Troicki is loser as Roger Federer seeks a third title in Doha

Federer, twice champion in Doha, took just 65 minutes for his win. Seeded second, Federer now has a 21-3 win-loss record at the tournament.

He will face third-seeded Jo-Wilfried Tsonga in the semifinals today after the Frenchman beat seventh seed Guillermo Garcia-Lopez of Spain 7-6 (4), 7-6 (9).

"I am happy with my form here and in this match," Federer said. "It wasn't a tough match and I was quite comfortable.

"I was in control of my shots and created many opportunities. This was easy compared to the first two matches."

Federer has won two of his three previous meetings with Tsonga, who is making his comeback from a knee injury that brought his 2010 season to an early end.

"He's a wonderful player, a great character," Federer said of Tsonga. "He has performed well at the big tournaments, especially on the hard surface at the Australian Open. Unfortunately, he's had injuries and didn't play as much but he's tough."

Federer broke Troicki twice in each set while holding serve easily against a tired-looking opponent, who has won just one ATP title.

The No 2-ranked Federer did not serve a single ace but did not have to save a break point as he kept up his record of not dropping a set in the tournament.

Meanwhile, top seed Maria Sharapova's flirtation with the New Zealand public came to a premature end with a surprising 6-2, 7-5 loss to unseeded Hungarian Greta Arn in the quarter-finals of the Auckland Classic.

The triple grand slam winner, who had chosen to warm up for the Australian Open by entering the Auckland tournament rather than her normal schedule of playing exhibition matches, struggled with her rhythm in the swirling wind.

She was broken twice in the first set by the 31-year-old Arn and made numerous unforced errors in the second to crash out in a match lasting 91 minutes.

"I started off really slow, got down two breaks and I think she gained a tremendous amount of confidence from that," said Sharapova. "I had my chances in the second (set), but I didn't play the same way I had played to get there.

"Obviously I would have loved to play a few more here and be the winner. But that's the way it goes. You look forward to the next one. That's the good thing about tennis." Arn will now meet fourth-seeded German Julia Goerges who beat Ukraine's Kateryna Bondarenko 5-7, 6-2, 6-2 in the last quarter-final that was played in the final evening session.

Sharapova's presence had helped effectively sell-out the tournament by the first day and her defeat disappointed those hoping for a final against champion and second seed Yanina Wickmayer.

Wickmayer had earlier made sure of her place in the semi- finals when she beat Romania's Simona Halep 6-0, 6-2 in a little over an hour in the first match on centre court to set up a showdown with China's Peng Shuai, who beat British qualifier Heather Watson 6-4, 7-5. "I feel very happy, this is the first week of the year and I'm really happy to be playing well," said Wickmayer "I'm in the semis so I guess this tournament is lucky for me."

In India, Kei Nishikori of Japan rallied to beat Alejandro Falla of Colombia 4-6, 6-3, 6-2 to reach the quarter-finals of the Chennai Open. Nishikori, who beat defending champion Marin Cilic in the opening round, was down a break and trailing 3-0 in the second set when he turned it around. Janko Tipsarevic of Serbia defeated Alexandre Kudryavtsev of Russia 6-2, 7-6 (3), and eighth-seeded Robin Haase of the Netherlands beat Yuichi Sugita of Japan 4-6, 6-3, 6-4.