Serena Williams’s hopes of securing a calendar Grand Slam were ended in stunning fashion by Italy’s Roberta Vinci in the US Open semi-finals.
Vinci, the world number 43 and playing her first Grand Slam semi-final, caused a huge upset with a 2-6 6-4 6-4 win.
Williams, 33, had been two wins from completing a clean sweep of all four majors in 2015.
Vinci, 32, will play Flavia Pennetta in an all-Italian final at Flushing Meadows on Saturday.
Pennetta, the 26th seed, outplayed Romanian second seed Simona Halep in the first semi-final to win 6-1 6-3.
Saturday will see the first Grand Slam final between two Italian players since the Open era began in 1968.
Williams’s hopes of winning a first calendar Slam ended just two victories short, and in the most sensational of upsets.
The American had survived 11 final sets in Grand Slam matches during 2015, but at the 12th time of asking came up against an opponent who simply grew stronger.
When Williams smashed her racquet after dropping the second set it was clear that the tension was beginning to boil over, and her cries of “come on” in the third set took on an increasingly desperate air.
There was still the possibility that Vinci would crumble in the decider, but she served out to love with two nerveless half-volleys for the win of her life.
“It was an incredible match,’ said the Italian. “I lost the first set, and tried to stay in every point. I tried to stay focused and not think about Serena. It is the best moment of my life.”
Williams remains the holder of all four major titles for another 24 hours, having completed the “Serena Slam” at Wimbledon – she won the Australian Open in January, before taking the French Open title in June and Wimbledon a month later.
“I don’t want to talk about how disappointing this is for me,” said Williams in her post-match news conference, which lasted just four minutes.
“If you have any other questions I’m open to that.”
On whether she felt the strain of winning the calendar Grand Slam, she added: “I never feel pressure and never felt that pressure to win here. I said that from the beginning.”
Vinci, on the other hand, delighted the crowd with a charming on-court interview.
“I am sorry for the American people, for Serena, for the Grand Slam, but today is my day, sorry guys.
“When I wake up today I say, ‘OK, I have a semi-final, try to enjoy. Don’t think about Serena.’ I did not expect that I win.
“In my mind I say, ‘Try to put all the balls in play. Don’t think about Serena in the other court. And run.’ And then I won.”
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