losing to Venus Williams. She lost 1–6, 0–6 which is the biggest defeat for a current number one in WTA Tour history. Her performance invoked criticism about her status as the No. 1 player in particular from the new Wimbledon champion and world No. 2, Serena Williams who openly mocked her credibility as the top player. After winning a small tournament in Portorož, Safina failed to defend her title in Los Angeles. Despite this, she became the first player to qualify for the WTA Tour Championships. The following week in Cincinnati, Safina advanced to her eighth final of the season, losing to former world No. 1 Jelena Janković. Safina was the top seed at the US Open, but lost in the third round to Petra Kvitová. Following back-to-back second round losses in Tokyo and Beijing, Safina lost the No. 1 rank to Serena Williams. She regained it two weeks later on October 26. At the WTA Championships, she had a chance to end the season as No. 1 for the first time in her career, but retired due to a back injury in her first round robin match, which she claimed had been bothering her for three months. 2010: Beginning of career decline Safina started 2010 by losing in the quarterfinals to Elena Dementieva in Sydney. At the Australian Open, she reached the fourth round where she retired with a back injury which also forced her to withdraw from tournaments in Dubai, Indian Wells, and Miami. In her return to competitive tennis for the clay season, Safina lost in the quarterfinals of Stuttgart to Shahar Pe'er. She struggled through the rest of the clay season, losing her opening matches in Rome, Madrid and the French Open, causing her ranking to drop to No. 20. She later withdrew from Wimbledon after being dealt her fifth straight loss at a warm-up tournament in 's-Hertogenbosch. She began the US Open Series at the Bank of the West Classic in Stanford, California, where Safina was given a wildcard. She played veteran Kimiko Date-Krumm in the first round. Safina lost in three sets. In the first round of the Mercury Insurance Open in San Diego, California, Safina ended her 6 match losing streak when she defeated Alona Bondarenko in the first round. She then lost to Agnieszka Radwańska in the second round. Safina's next tournament was at the Western & Southern Financial Group Masters and