NEW YORK (Reuters) - Roberta Vinci delivered one of the biggest upsets in tennis history with a U.S. Open semi-final win over Serena Williams on Friday that ended the American's Grand Slam bid and set up a surprising all-Italian final.
Two match wins from becoming the fourth woman to win all four majors in one year, a nerve-wracked Williams crumbled as unseeded Vinci, playing in her first grand slam singles semi-final, battled to an improbable 2-6 6-4 6-4 win.
"I don't want to talk about how disappointing it is for me," a grim-faced Williams told reporters. "I told you guys I don't feel pressure. I never felt pressure.
"I never felt that pressure to win here. I said that from the beginning."
The day got off to an ominous start when Flavia Pennetta stunned Romanian second seed Simona Halep 6-1 6-3 and the upset trend continued as an inspired Vinci soon followed her Italian compatriot out onto Arthur Ashe Stadium court.
Vinci, a 300-1 long-shot to win the U.S. Open when the two-week tournament began, remarkably pulled off one of the wildest scenes ever witnessed on a tennis court by ending Williams' streak of 33 consecutive match wins in the grand slams.
A five-times doubles grand slam winner, Vinci, 32, arrived at Flushing Meadows having never before been beyond the quarter-finals in singles play at 43 majors.
In the other corner stood Williams, a 21-times grand slam champion who had only lost two matches all season and never dropped a set against Vinci in their four previous meetings.
Forced to wait a day to get on court after rain wiped out Thursday's semi-finals schedule, the weight of expectation appeared to weigh on the muscular shoulders of a 33-year-old who was chasing the first Grand Slam since Steffi Graf in 1988.
Everything was going according to script as Williams easily took the opening set but things began to unravel quickly after a composed Vinci registered a key break in the fifth game of the second set that allowed her to even the match.
With the contest slipping away, Williams tried to will herself back into the match, screaming and fist-pumping after each point and feeding off the support of the crowd.
But with nothing lose, an undaunted Vinci continued to pressure Williams, who could not pull off the great escape like she had so many times before scowling as she exited a stunned stadium.
"This is an incredible moment for me," Vinci said after needing time to compose herself for the on-court interview. "It's amazing. It's like a dream. I'm in the final. I beat Serena."
Lost in the drama of the Williams match was a brilliant performance by Pennetta, who needed less than an hour to dispatch Halep.
Pennetta, 33, entered the contest as the clear underdog but the 26th seed showed her experience and was not overwhelmed on the big stage having reached at least the quarter-finals at Flushing Meadows in six of the last seven years.
Aside from her U.S. Open resume there was little to hint at a U.S. Open final by Pennetta, who by her own admission had an unimpressive run-up to the year's final grand slam.
"It's amazing. I didn't think to be so far in the tournament," said Pennetta. "Today I think I played really well."
Editing by Frank Pingue and Tony Jimenez