Djokovic, unbeaten in 2011, advances in Serbia

Novak Djokovic won his 26th straight match to remain unbeaten in 2011, defeating Slovenia's Blaz Kavcic 6-3, 6-2 Friday in the Serbia Open quarterfinals. This is the best start to an ATP tour season since Ivan Lendl in 1986.

This was a victory, however, that almost didn't happen. While ahead 4-1 in the second set, Djokovic threatened to quit because he said the lines became too slippery once it started raining.

"I don't want to play, I don't want to get injured," Djokovic shouted at the chair umpire, leaving the court and taking a seat.

Play resumed only after the lines were wiped, and Kavcic then managed his only break. The 85th-ranked Kavcic never seriously threatened Djokovic, who had one break in the first set and three in the second.

"There was some pressure, but I've learned to deal with it by now," said Djokovic, whose family helps organize this event.

Djokovic has won 63 of 69 sets and four tournament titles in 2011, including the Australian Open. He has unseated Roger Federer, the last man to beat him, for the No. 2 ranking.

In the semifinals, Djokovic will play fellow Serb Janko Tipsarevic, who edged Somdev Devvarman of India 6-3, 3-6, 6-4. Feliciano Lopez will face Filippo Volandri of Italy in the other match. Lopez upset fourth-seeded fellow Spaniard Albert Montanes 6-4, 6-4, and Volandri beat Spain's Marcel Granollers 6-2, 6-4.

The seventh-seeded Tipsarevic was broken while leading 5-3 in the third set as he was serving for the match. But Devvarman lost his composure in the next game, and was broken to love.

"Somdev plays with a lot of confidence he gained lately on the tour," Tipsarevic said. "When I dictated the play, I was winning. When I stuck to the baseline, I was in trouble."

Lopez converted two of his nine break points against Montanes to reach his first ATP semifinal of the year.

Volandri will play his first semifinal in more than two years.

"I'm really happy with this win," Volandri said. "It's a good feeling to be in the semis again after so long."