Dubai, UAE, 22 February 2013 | AP/AFP

Australian Sam Stosur has fallen to Roberta Vinci of Italy 6-2 6-4 on Thursday in the quarterfinals of the Dubai Duty Free Tennis Championships.

It is the third straight year Stosur has gone down at this stage of the Dubai event, and follows her quarterfinal exit in Doha last week.

The 2011 US Open champion made 28 unforced errors and was broken twice in each set. Her first serve percentage was only 58 in the second set and she faced eight break points.

“Way too many errors,” Stosur said.

“She did well to not be bothered by anything I was trying to do. She used her slice very well which kept all the points neutral. I made way too many mistakes on those neutral balls.”

Despite the latest setback, the 28-year-old said she felt she was improving after her disappointing start to the year.

“January didn’t really go as well as I wanted it to. I wasn’t playing up to the standard and level that I think I’m capable of,” she said. “The last couple of weeks, it’s gotten better. I’ve played many more good matches than bad so it’s certainly on the way up.”

In the semifinals, Vinci will face doubles partner Sara Errani, with seventh-ranked Italian beating No.12 Nadia Petrova of Russia 6-4 0-6 6-3.

“I spoke with my coach to play more aggressive,” said Vinci, who beat Svetlana Kuznetsova and sixth-ranked Angelique Kerber before besting Stosur in the quarterfinals.

“I played a lot on her backhand. She has an unbelievable forehand. So on my mind, I try to play against her backhand because she has a lot of problem with backhand, and try to change some slice and also some top when I have time.”