Kirsten Flipkens of Belgium defeated two-time former champion Ana Ivanovic 6-4 6-0 on Friday in the quarter-finals of the WTA event in Linz.

Top-ranked Victoria Azarenka, fifth-seeded Julia Goerges and Irina-Camelia Begu of Romania also advanced to the semi-finals.

Flipkens, who is ranked 66th and had to qualify for the main draw, trailed 3-1 before winning 11 of the next 12 games.

“It’s incredible that I’ve beaten her,” Flipkens said.

“I tried to play my own game and switched a lot between attacking and defensive shots. Then Ana started to make more mistakes. I think that was because of the way I was playing.”

Ivanovic won the tournament in 2008 and 2010. Flipkens, who won her maiden title in Quebec City last month, will play Goerges for a place in Sunday’s final.

Azarenka reached her 10th semi-final of the season by defeating Petra Martic of Croatia 6-2 6-2.

Azarenka won the first 10 points to help build a 4-0 lead before Martic clawed her way back into the match.

The Croat had a break in the second set to level at 2-2 but did not win another game.

“I feel like I adjusted really well,” said Azarenka, who had never played Martic before.

Azarenka has not dropped a set in 11 consecutive matches. She won in Beijing last week and pulled out in the quarter-finals at Tokyo the week before.

“Every day I have to push myself,” Azarenka said. “It’s not easy, even when it seems easy out there on court.”

Azarenka will next play Begu, who defeated Bethanie Mattek-Sands of the United States 6-4 1-6 6-2.

The 57th-ranked Begu, who won her first career title in Tashkent last month, lost in qualifying but still entered the main draw as a replacement for Anna Tatishvili of Georgia.

Goerges, who hasn’t lost a set this event either, beat Sofia Arvidsson of Sweden 6-1 6-4.

From 1-1 in the opening set, the fifth-seeded German won seven straight games. Arvidsson broke back to level at 4-4 in the second but then dropped her serve for the fourth time in the match.