In the semifinals on Friday, Haas will meet seventh-seed Elise Mertens (Belgium), who recovered from a first-set loss to get past her doubles partner Marina Melnikova (Russia) 3-6, 7-5, 6-2.

For Haas, who made it to two ITF finals in Greece last month, this was the second time she had scalped a seeded player in three rounds here.

Former world junior number one Ivana Jorovic (Serbia) had it easy after the first set tie-breaker in beating Nicha Lertpitaksinchai (Thailand) and set up a semifinal clash with Anastasiya Vasyleva (Ukraine), who staved off Sabina Sharipova (Uzbekistan) 6-3, 6-4.

Patricia has a rich vein of experience behind her, being good enough to have played in 17 Grand Slam tournaments and having won 17 ITF singles titles in the past decade. But, all that was of little consequence as she was up against a determined and younger compatriot in the quarterfinals.

The teenager, who held her nerve to win the second set tie-breaker, found it hard to come to terms with the fact that she had beaten her senior.

"I honestly did not think I would win. I had nothing to lose but I got nervous and felt the pressure when I was leading," said Haas after her victory.

Latest News from Sports News Desk