Denisa Allertova pulled off the biggest win of her fledgling career, dumping world number two Simona Halep out of the Guangzhou International Women's Open on Thursday.

Allertova beat then-number 10 in the world Carla Suarez Navarro at the US Open last month, and was again impressive in China, despite the clash with Halep representing her first meeting with a player in the world's top five.

A run of taking six games out of seven helped Allertova take out the opening set and race to a 5-1 lead in the second, before rounding off a 6-4 6-3 victory with apparent ease.

"I have amazing feelings, because I won against Simona Halep," world number 74 Allertova told the WTA's official website.

"She's a great player, ranked number two. I can breathe now!
 
"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 Suarez 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."

Allertova faces another stellar test in the semi-finals in the form of third seed Sara Errani, who thrashed Zheng Saisai 6-1 6-0 to reach the final four.

Jelena Jankovic and Yanina Wickmayer will battle it out for a place in the final, after overcoming Svetlana Kuznetsova and Monica Niculescu respectively.