Murray rolls; another upset for Petrova

MELBOURNE, Australia - Andy Murray overcame big-serving John Isner, 7-6 (4), 6-3, 6-2, early today to set up a possible Australian Open quarterfinal match against defending champion Rafael Nadal.

Nadia Petrova also advanced with another upset win, beating third-ranked Svetlana Kuznetsova, 6-3, 3-6, 6-1, to reach the quarters.

In the other section of Petrova’s half of the draw, Zheng Jie set another national mark by becoming the first Chinese player to reach the quarterfinals at Melbourne Park with a 7-6 (6), 6-4 victory over Alona Bondarenko.

Kuznetsova committed 52 unforced errors compared to 22 winners and had her serve broken three times in the deciding set after rallying in the second to level the all-Russian match.

No. 19 Petrova had a stunning 6-0, 6-1 win over U.S. Open champion Kim Clijsters in the third round. Her run to the quarterfinals equals her best performance at the Australian Open. Her best run at a Grand Slam was to the French Open semifinals twice.

Murray wants to expand on a résumé that includes one Grand Slam final loss.

The 22-year-old Scot rated Isner’s serve among the best in the game, so he was delighted to wear down the American after a crucial service break in the eighth game of the second set. He fended off break-point chances in the next game to serve out the set.

“It’s tough. I had my coach serving at me from the service line this morning to try to get used to it,” Murray said of the 6-foot-9 Isner’s serve. “But once you get out there it’s kind of tricky.”

Fifth-seeded Murray broke serve again in the seventh game of the third set when Isner netted a forehand and then smashed his racket into the court in disgust.

“It’s been good. I moved really well since the start of the tournament,” Murray said. “I didn’t drop a set yet … not too much to complain about.”

So far.

Murray faces a daunting quarterfinal. Nadal was scheduled to play Croatia’s Ivo Karlovic in the following match.

The loss was Isner’s first of the year, which started with his first career ATP title at Auckland.

Zheng had already matched her own previous best run at Melbourne Park by reaching the fourth round, but is still a win away from equaling her best performance at a Grand Slam.

The 26-year-old Zheng made a stunning charge to the Wimbledon semifinals in 2008, becoming only the second wild-card entry and first Chinese player to reach the semis at a major and ousting then-No. 1 Ana Ivanovic along the way.

“I think Australia is lucky for me because I win the first Grand Slam doubles title in Australia,” said Zheng, who won the Australian Open and Wimbledon doubles titles in 2006 with Yan Zi. “So I’m so happy I’m in the quarterfinal of Australia also.”

She and No. 16 Li Na both reached the fourth round here, the first time two Chinese players have reached that stage at the same Grand Slam tournament. With one on each half of the draw, Zheng said they can both go further.

Bondarenko, seeded No. 31, had been on an eight-match winning streak after a title run at Hobart last week, which included a quarterfinal win over Zheng.

Top-ranked Roger Federer and Australian hope Lleyton Hewitt both won Saturday to set up a meeting in the fourth round. The winner of that — Federer is on a 14-match winning streak against Hewitt — could meet Nikolay Davydenko in the quarters.

Sixth-seeded Davydenko is on a 12-match winning streak, including wins over Federer and No. 2 Rafael Nadal. But he’ll have to get past 2009 semifinalist Fernando Verdasco to get a shot at Federer or Hewitt.

Davydenko beat Argentina’s Juan Monaco, 6-0, 6-3, 6-4; Verdasco advanced when Stefan Koubek retired with an illness after falling behind 6-1.

Hewitt had to play only 12 games in 54 minutes to advance over Marcos Baghdatis, the 2006 finalist, who retired with a right shoulder injury after falling behind 6-0, 4-2. Federer ousted Albert Montanes, 6-3, 6-4, 6-4.

No. 3 Novak Djokovic, who beat Federer in the semifinals en route to the 2008 title, defeated Denis Istomin, 6-1, 6-1, 6-2, and next plays Poland’s Lukasz Kubot. Kubot got a walkover when No. 20 Mikhail Youzhny withdrew with a wrist injury.

Jo-Wilfried Tsonga, the 2008 runner-up, beat Tommy Haas, 6-4, 3-6, 6-1, 7-5, and next will play Spaniard Nicolas Almagro, a 6-4, 6-3, 6-4 winner over Colombia’s Alejandro Falla.

The Williams sisters moved a step closer to a semifinal meeting, with defending champion Serena beating No. 32 Carla Suarez Navarro, 6-0, 6-3, and Venus advancing, 6-1, 7-6 (4), over Australian wild-card entry Casey Dellacqua.