GUANGZHOU: Czech Denisa Allertova stunned world No.2 Simona Halep 6-4, 6-3 in the quarterfinals of the Guangzhou International Women’s Open on Thursday.

The win against the Romanian top seed gave the 22-year-old, ranked 74 in the world, only her second victory against a top 10 player after she defeated Carla Suarez Navarro in the first round of the US Open recently.

After going up 5-4 in the first set, Allertova won six of the next seven games for a 5-1 lead in the second and then closed the match out with a backhand winner.

“I have amazing feelings because I won against Simona Halep — she’s a great player, ranked No. 2. I can breathe now!” Allertova told the WTA website after the match.

“I don’t know, I was just trying to focus every point, not looking who’s on the other side, just focusing on myself and playing my tennis. I was fighting every point and it worked. I’m so happy.

“It was my first time playing such a top player like this, but at the US Open I played against Suárez Navarro, also an amazing player, a top 10 player, and I beat her, but it’s the first time in my life to have a win like this.”

Unseeded Yanina Wickmayer of Belgium earlier defeated another Romanian in sixth seed Monica Niculescu 6-2, 6-2 while third-seeded Sara Errani powered past local hope Zheng Saisai 6-1, 6-0 for a semifinal meeting with Allertova.

Number four seed Jelena Jankovic of Serbia also reached the last four by defeating fifth-seeded Russian Svetlana Kuznetsova 6-2, 7-5.

Stephens in quarters

In Seoul, American Sloane Stephens cruised past Japanese veteran Kimiko Date-Krumm to advance to the quarterfinals of the WTA Korea Open on Thursday.

Third-seeded Stephens defeated 44-year-old Date-Krumm, champion in Seoul in 2009, 6-3, 6-4 in the second round of the tournament.

The 22-year-old American, ranked 32nd in the world, won her first WTA title at the Citi Open in Washington last month.

Aliaksandra Sasnovich of Belarus, ranked 136th in the world, meanwhile earned a surprise win over Magdalena Rybarikova, currently ranked 73rd, defeating the Slovak 6-3, 6-3.

Russia’s Elizaveta Kulichkova also breezed past the fourth-seeded American Varvara Lepchenko 6-0, 6-2, while Romanian Irina Begu, ranked 29th in the world, defeated Slovenian Polona Hercog after a tough battle, eventually winning 6-2, 6-7 (6/8), 6-2.

Ivanovic launches campaign

In Tokyo, defending champion Ana Ivanovic survived a brave challenge from Italian Camila Giorgi on Thursday at the Pan Pacific Open, managing a tough 7-5, 6-2 victory.

The victory put the Serb second seed in a quarterfinal against Dominika Cibulkova in a rematch of the US Open where Ivanivic was ousted by the Slovak.

In Tokyo, Ivanovic struggled to keep full control of the match particularly during the first set when she suffered five double faults, as Giorgi fired a succession of big serves and deep returns to keep their gap within close margins.

In the second set, Giorgi led 2-0, as the world No.12 Ivanovic vented her frustration.

Later, however, Ivanovic snapped back winning the next six straight games and the set 6-2 in one hour and 39 minutes.

In other matches, Agnieszka Radwanska, 2011 Pan Pacific winner, cruised by Elina Svitolina with a 6-4, 6-1 victory.

In a quarter-final, the seventh-seed Pole will face fourth-seed Czech rising star Karolina Pliskova, who beat Kurumi Nara of Japan 6-2, 6-4.

Radwanska won all of their three previous matches.

Cibulkova beat sixth-seed Carla Suarez Navarro 6-4, 6-4.