Djokovic, the No. 2 seed, erased all five break points he faced in the match. His opponent in the semifinals will be American Mardy Fish, who beat sixth-seeded David Ferrer 7-5, 6-2.
Djokovic won two Davis Cup matches in December, and his 22-0 record in 2011 is the best to begin a year since Ivan Lendl started 25-0 in 1986.
“When you watch him play, it's really not that surprising that he hasn't lost yet, because he's playing so well,” Fish said. “He's not going to win every single match this year. Whether it be this week or in July, he's not going to win every one. It's just not possible. So hopefully it can be against me.” As Djokovic closed in on his latest win, he unveiled his version of the Petko Dance - a celebratory jig introduced by Andrea Petkovic, who plays Maria Sharapova in the semifinals Thursday. Petkovic and Djokovic were both born in Serbia.
In the women's quarterfinals on Wednesday, Victoria Azarenka of Belarus beat two-time champion Kim Clijsters of Belgium 6-3, 6-3. Clijsters, who has been nursing a right shoulder injury since she won the Australian Open in January, had eight double-faults and only held three times in nine service games.
Azarenka, the 2009 tournament champion, will next face Vera Zvonareva, who beat Agnieszka Radwanska of Poland 7-5, 6-3.
Zvonareva, the No. 3 seed from Russia, overcame a set point with an ace in the first set against Radwanska, and won four consecutive games to take control of the second set. She improved to 4-0 in quarterfinals this year.
Fish, meanwhile, became the top-ranked men's American player by beating Ferrer in his quarterfinal match.
The 29-year-old Fish will climb to at least 11th, a career best, in the next rankings. His good friend, Andy Roddick, will fall from eighth to 14th after losing his opening match last week.
“I don't think I would ever feel like I was the No. 1 American,” Fish said. “Andy has had a pretty good career.
You can put his career on top of mine about six times. He's always going to be the top dog in my generation.” Fish, seeded 14th, dominated with his serve and took the lead for good when Ferrer hit back-to-back double-faults to lose the 11th game. At 29, Fish is into the Sony Ericsson semifinals for the first time.
Ferrer was so frustrated at one point in the second set, he directed a forehand lob toward a crying infant in the stands. The ball didn't come close to the baby, but the crying stopped.
Ferrer blamed his defeat not on the distraction, but on a case of indigestion. “It was in one moment of the match, but nothing special,” Ferrer said. “It was not the problem.”
