Errani and 18th seed Samantha Stosur in the second and third rounds in straight sets, before retiring against eventual finalist Venus Williams. At the Rogers Cup in Toronto, Ivanovic defeated Magdaléna Rybáriková in the first round and went on to face Lucie Šafářová in the second round where she was eliminated. At the US Open, Ivanovic lost in the first round of a Grand Slam for the first time in her career by succumbing to Kateryna Bondarenko. After the match, former Wimbledon champion Pat Cash criticized Ivanovic's new service motion, stating that watching it was a "painful experience" and that it "weakened her threat." He also felt that Ivanovic was "over-analysing" her game and that her main problem was "her lack of confidence." At the Premier 5 Toray Pan Pacific Open in Tokyo, Ivanovic suffered her third successive defeat by losing to Lucie Šafářová in the first round. Citing an upper respiratory tract infection, Ivanovic pulled out of the China Open and announced on her website that she was taking the rest of the year off. She finished the year with a 24–14 match record, her worst since she turned pro, and did not win any titles. Ivanovic only reached three quarterfinals, one semifinal, and one final, and only won back-to-back matches six times. Ivanovic ended the year ranked 22, the first time she had been ranked outside the top 20 since July 2005. 2010: Return to the top 20 Ivanovic started the year in Brisbane. Seeded third, Ivanovic reached her first semifinal since Indian Wells in 2009. She eventually bowed out to wildcard Justine Henin in Henin's first tournament since her return from retirement. Ivanovic was seeded 20th at the Australian Open, but lost to Gisela Dulko in the second round in three sets. She then participated in the opening round of the Fed Cup in Serbia's tie against Russia, and she went 0–2 in her singles matches and also lost doubles match. Ivanovic announced that she would be working with Steffi Graf's former coach Heinz Günthardt on a trial basis during the spring North American hard-court season, suspending her relationship with the Adidas Player Development Program indefinitely. In her first match as Gunthardt's pupil, a one-set semifinal against reigning US Open champion Kim Clijsters in the 2010 Billie Jean King Cup at Madison Square Garden, Ivanovic lost in a tiebreak, despite having held match point. After the match,