Following is a list of biggest shocks in women's tennis after Italian outsider Roberta Vinci, ranked 43rd, beat world number one Serena Williams in the US Open semi-finals on Friday to deny the American a chance to complete a calendar year Grand Slam.
Roberta Vinci beats Serena Williams 2-6, 6-4, 6-4 in the Flushing Meadows semi-finals to halt the American's 33-match winning streak at the majors.
Before arriving in New York in 2015, the 32-year-old Italian's best grand slam performance was two quarter-final appearances in 43 attempts. Despite the odds stacked against her, doubles specialist Vinci condemned 21-times major singles champion Williams to her first defeat at a grand slam since Wimbledon in 2014.
Jelena Dokic beats Martina Hingis 6-2, 6-0 in the first round at Wimbledon in 1999. The Swiss became only the third top seed to lose in the opening round of the grasscourt major, falling to a 16-year-old Australian qualifier ranked 129th in the world.
Lori McNeil beat three-times defending champion Steffi Graf 7-5, 7-6, (7-5) in the first round at Wimbledon in 1994.
The German became the first defending women's champion at Wimbledon to fall at the first hurdle. Graf owned a 21-match unbeaten streak at the home of grasscourt tennis, and had already won five titles there when she was humbled by her American opponent.
Kathleen Horvath beats top ranked and defending champion Martina Navratilova 6-4, 0-6, 6-3 in the fourth round of the 1983 French Open.
Going into the match, Navratilova had won three of the previous four majors and all 36 of her matches stretching back to the start the year. The defeat to 45th-ranked Horvath prevented Navratilova from achieving a perfect season as it was her only loss during a year when she went on to record an 86-1 win-loss record.
Unseeded Kathy Jordan upset second seed Chris Evert 6-1, 7-6, (7-2) in the third round of Wimbledon in 1983.
American Evert had reached the semi-finals or better at all 34 grand slam events she had previously contested since 1971 before succumbing to her 23-year-old opponent. The result also ended Evert's hopes of completing a non-calendar year grand slam as she had won the three previous majors.
It later emerged Evert needed medical attention before the match after suffering from a stomach virus.
