US Open champion Sam Stosur is building on a solid final run in Doha last week as she booked herself a spot in the quarter-finals of the Dubai Duty Free Tennis Championships courtesy of a three set win over tricky Czech Lucie Safarova on Wednesday.

The fourth-seeded Aussie saved all nine break point opportunities she faced throughout the two hour 1 minute encounter to register a 6-1, 6-7 (5/7), 6-1 victory – only her second in five meetings against Safarova.

“Lucie can be a very dangerous player and has got a big game. When she puts it all together it’s hard to play against,” said Stosur, who next takes on No8 seed Jelena Jankovic.

“I thought tonight I served really well. That second set I lost it, but I don’t think I did really that much wrong.  I had a few opportunities to try and break late in the second set and wasn’t able to take them, but then finally did early in the third.”

Jankovic earned her spot in the last-eight with a convincing 6-4, 6-2 rout of Flavia Pennetta in one hour 40 minutes.

The Serb benefitted from some poor serving from Pennetta – who hit a dismal 43 per cent first serves in – to make her fifth quarter-final in Dubai.

“It wasn’t an easy match at all. I think from the start we were, you know, back to back. There were some really tight games. It could have gone either way,” said the 26-year-old.

“I hung in there. I was down a break in the first in the beginning, and then I managed – I lifted up my game and I started playing a lot more aggressively and I started controlling the points a lot better and I put pressure.”

Meanwhile, No5 seed Agnieszka Radwanska survived a gruelling match against Shahar Peer to advance to the last-eight.

In a contest that lasted almost two hours and saw ten breaks of serve Radwanska was broken while she was serving for the match at 5-3 but recovered immediately to improve her record against Peer to three matches apiece and set up a quarter-final with No9 seed Sabine Lisicki.

“The court (Court 1) is a little bit different. It’s a little bit faster than the Centre Court. I couldn’t really feel the ball in the beginning,” said the 22-year-old Pole, who beat Aleksandra Wozniak in a tough three-set battle on Centre Court in the first round.

“But then I think we are just both fighters so we were just fighting for each ball. Maybe it was not the greatest match ever, but I think we were just fighting.

“It was very, very tight in the both sets, game by game, point by point. I think I was in trouble in both sets.”