Who Is Roberta Vinci? Serena Williams Upset At US Open By Italian Tennis Player

In a shocking upset, Roberta Vinci knocked out No. 1-ranked Serena Williams in the Friday semifinal round of the U.S. Open tennis tournament, winning 2-6, 6-4, 6-4. The unseeded Italian tennis player pulled off the stunning victory to end Williams' bid for a calendar slam, meaning she would have held all four major tournament titles in the same year if she had won.

The win for Vinci was not a result many saw coming. "I think this is the end of the road for Roberta Vinci," said former player and analyst Chris Evert on ESPN leading up to the match, reported the New York Times.

Vinci, 32, lives in Taranto, Italy, and was ranked No. 43 in the world prior to Friday's match, according to the Women's Tennis Association website. The right-handed player has a solid, veteran game and Williams said beforehand that Vinci could prove a difficult opponent.

“She’s going to present a completely different game than my last three matches, four matches,” Serena said, according to the Times. “She has nothing to lose -- I don’t, either. So we’re just going to go out and have a lot of fun.”

With a career record of 512-353, Vinci has won just one title in 2015 and has never won a major, according to statistics compiled by ESPN. She turned pro in 1999 and has won just nine tournament titles in her career. Williams, on the other hand, has a career record of 737-122 and was chasing her 22nd major title before being knocked out. A championship would have tied her with tennis legend Steffi Graf at 22 titles and given her a calendar Grand Slam.

Heading into Friday's match, Vinci knew she had to play her top game to beat perhaps the greatest tennis player ever. "Serena is Serena," Vinci said Tuesday, according to USA Today. "You have to play better, then better, then better."

The 2015 U.S. Open has been the best singles major showing in Vinci's career. Playing doubles, she has won five times in majors, according to NPR. In her post-match interview after besting Williams, Vinci credited her win to focusing on the game play rather than her legendary opponent on the other side of the net. She was able to not "think about that [it was] Serena on the other court," Vinci said, according to NPR.