With a historic calendar Grand Slam attempt shattered before the weekend, a US Open women's final missing much of its anticipated marquee magic now faces the threat of thunderstorms.
Italy's Roberta Vinci and Flavia Pennetta are set for a Saturday afternoon trophy showdown at Arthur Ashe Stadium in its final weekend of matches before a retractable roof is ready for the 2016 tournament.
"One Italian will win for sure," Vinci said. "It's an incredible moment."
Vinci defeated top-ranked defending champion Serena Williams 2-6, 6-4, 6-4 while Pennetta ousted Romanian world number two Simona Halep 6-1, 6-3.
Williams, who holds all four major titles until the women's final is played, was bidding for the first calendar Grand Slam since Steffi Graf in 1988 and a 22nd Slam singles crown to match Graf's Open Era record.
But all that vanished when Vinci pulled one of the great stunners in tennis history.
"I don't want to talk about how disappointing it is for me," Williams said.
And now a dreary weekend forecast calls for a 65 percent chance of thundershowers on Saturday and a 75 percent chance for the same on Sunday for the men's final between top-ranked Novak Djokovic and second-ranked Roger Federer.
Rain had forced the men's final to be delayed until Monday from 2008 through 2012, pushing the US Open to construct the new roof, the superstructure framework for which stands around Ashe this year.
In addition to the first all-Italian women's Grand Slam singles final, the men's doubles final is also on Saturday's jeopardized schedule.
That features Britain's Jamie Murray and Australian John Peers against the French duo of Nicolas Mahut and Pierre-Hugues Herbert.
Pennetta, 33, and Vinci, 32, are each in their first Grand Slam final seeking the top prize of $3.3 million (2.9 million euros), with the runner-up taking home $1.6 million.
