Stuttgart, April 30 (Inditop) Gisela Dulko of Argentina stunned high-flying Belarussian Victoria Azarenka 6-4, 6-3 to move into the quarter-finals of the Porsche Grand Prix.

The 34th-ranked Dulko prevailed in 76 minutes Wednesday over the fourth-seeded Azarenka, who came to Stuttgart as one of the hottest players of the year with three titles including the Miami Masters.

Title holder Jelena Jankovic made no mistakes as she cruised to a 6-1, 6-1 first-round victory over Slovak Dominika Cibulkova.

Russian seeds Svetlana Kuznetsova and Nadia Petrova posted hard-fought three-set victories to reach the second round.

In the day’s only second-round match, Azarenka recovered from a break to tie at 3-3, but the undeterred Dulko took the set after all. The players traded breaks early in the second set before Dulko never looked back after breaking for 3-2.

“I am very motivated to play these kind of matches,” said Dulko, who had lost both previous matches against Azarenka in straight sets.

“There was no secret, I played really well. Everything worked for me. I was solid and confident. I just believed in myself, that I can beat top players.”

Azarenka ran out of steam against Dulko, who excels on clay which in the indoor environment of Stuttgart provided her with perfect

conditions.

“I love it. No wind, no sun. You just play and forget everything,” she said.

Jankovic was never in trouble against the 17th-ranked Cibulkova as she won with a forehand winner after 70 minutes of play.

Jankovic lost the world No.1 ranking early in the year but is now trying to turn the season around after winning her first title two weeks ago in Marbella, Spain, and two Fed Cup matches as well.

“I am happy to be back on clay,” said Jankovic. “I served well and feel quite good.”

The fifth-seeded Kuznetsova needed five match points to defeat German qualifier Andrea Petkovic 6-4, 5-7, 6-1.

Petrova, the sixth-seeded 2006 champion and 2008 runner-up, was on court 20 minutes longer in a 6-4, 5-7, 6-4 victory against China’s Zheng Jie.

Kuznetsova won the first set after some late hiccups, but then double faulted to give Petkovic a 6-5 edge in the second as the German squared the sets with an ace a game later.

But Kuznetsova regrouped swiftly and raced off to a 5-0 lead. She wasted four match points in the next game but then succeeded on her fifth when Petkovic hit a backhand wide.

“I had too many ups and downs, especially in the second set. I am quite disappointed with myself,” said Kuznetsova.

Petkovic said: “I didn’t have the experience and the patience at the start of the third set. She was there when it mattered.”

But rising Sabine Lisicki, the recent winner in Charleston, kept the German flag flying with a 6-4, 6-3 victory over Swiss Patty Schnyder to set up a Thursday date with Jankovic.

Slovak Daniela Hatuchova ousted Alize Cornet of France 6-3, 6-1 and now meets world number one Dinara Safina of Russia. Flavia Pennetta of Italy routed Russian Anna Chakvetadze 6-0, 6-2.