MELBOURNE, Australia -- Vera Zvonareva ran off 11 straight games in a 6-3, 6-0 win over Marion Bartoli at the Australian Open earlier today to reach the semifinals for the first time in 25 majors.

The 24-year-old Russian's best performance in six previous trips to Melbourne was the fourth round -- she'd gone out in the first round at the Australian Open three times, including last year.

Seventh-seeded Zvonareva, who hasn't dropped a set in five matches, rallied from an opening service break to dominate 2007 Wimbledon finalist Bartoli in the remainder of their quarterfinal

"I'm very excited about it," Zvonareva said. "I think it was a great day for me."

Bartoli of France, seeded 16th, had ousted top-ranked Jelena Jankovic in the fourth round.

In the following match on Rod Laver Arena, defending champion Novak Djokovic was against No. 7 Andy Roddick in the first of the men's quarterfinals.

Roger Federer, seeking a record-equaling 14th Grand Slam singles title, was against No. 8 Juan Martin del Potro in a night match.

Andy Murray may have to wait awhile before he's picked again to win a Grand Slam tournament.

Touted by British bookmakers as a favorite at the Australian Open, Murray lost to No. 14 Fernando Verdasco of Spain in five sets Monday in the fourth round.

He twice blew a one-set lead and missed chances to break serve in the pivotal sixth game of the deciding set. He then dropped serve in the subsequent game and was beaten 2-6, 6-1, 1-6, 6-3, 6-4.

All of which was a big letdown for Murray, who defeated No. 1 Rafael Nadal and No. 2 Roger Federer in an exhibition in Abu Dhabi this month leading to the season's first major.

"I don't know if I'll be the favorite for a Slam in the next year or so after today," he said.

Nadal had a far easier time, downing 2007 runner-up Fernando Gonzalez of Chile 6-3, 6-2, 6-4. He has yet to drop a set ahead of his quarterfinal against sixth-seeded Gilles Simon.

Verdasco will meet fifth-seeded Jo-Wilfried Tsonga, the runner-up here last year who defeated No. 9 James Blake 6-4, 6-4, 7-6 (3).

Of the top eight seeded players, Murray will be the only one missing from the quarterfinals at Melbourne Park.

He wasn't the only casualty Monday -- Melbourne Park nearly had to establish its own emergency room.

Three matches finished early because of illness or injuries. The opener at Rod Laver Arena finished with Simon holding a 2-1 set advantage when friend and fellow Frenchman Gael Monfils decided he couldn't continue with an injured right wrist.

In the following match on center court, Serena Williams lost the first set 6-3 to 13th-seeded Victoria Azarenka but was up a break in the second when the 19-year-old Belorussian withdrew.

"The doctors didn't want me to keep going, but I wanted to keep trying and see how I do," said Azarenka, who was dizzy and sick from a virus.

Williams, who has won in Australia every alternate year since 2003, next plays Svetlana Kuznetsova, the 2004 U.S. Open champion.

Kuznetsova advanced when Zheng Jie retired at 4-1 after injuring her left wrist in a tumble in the third game, ending her hopes of a victory on the Chinese New Year.

Olympic champion Elena Dementieva extended her season winning streak to 14 matches with a 6-2, 6-2 win over Slovakia's Dominika Cibulkova to reach the quarterfinals here for the first time in 11 trips.

The fourth-seeded Russian next faces Carla Suarez Navarro, who ousted seven-time Grand Slam winner Venus Williams in the second round.