Upset No.16 - Kvitova's first round loss
Event: US Open 2011
Why was it an upset: It is not often in tennis a Wimbledon champion loses in the first round of the next Grand Slam event of the year. Unfortunately, for Petra Kvitova, it was a hard reality to digest as she was upset by Alexandra Dulgheru in the first round of the U.S. Open. The 48th-ranked Romanian won 7-6 (3), 6-3.