US Open Tennis 2015 Results: Top Quotes, Moments from Women's Semis

Friday's play at the 2015 U.S. Open knocked the sports world off its axis, thanks to a pair of stunning results in the women's semifinal round.

With the two top seeds facing heavy underdogs and a chance to make for an all-chalk final, the expected didn't take place. Instead, action at Arthur Ashe Stadium produced one of the most shocking upsets of the sports year, and perhaps history.

Here are the results from Friday's women's semifinals:

Match Result	Score
Roberta Vinci def. No. 1 Serena Williams	2-6, 6-4, 6-4
No. 26 Flavia Pennetta def. No. 2 Simona Halep	6-1, 6-3

That whole part about one of the biggest upsets in sports history wasn't an exaggeration.

What happened throughout early Friday afternoon at Flushing Meadows will likely be remembered for a long time as just that. That was thanks to unseeded Italian Roberta Vinci, who shockingly ended Serena Williams' quest for a calendar Grand Slam in a three-set upset.

Julio Cortez/Associated Press

Vinci took the match 2-6, 6-4, 6-4 in two hours flat, sending the sports world into a state of disbelief along with the spectators packing the stadium. The result became even more shocking after Williams took the opening set in exhilarating fashion, only to allow Vinci to claw her way back into the match.

While the focus may be on Serena's surprise upset, Vinci couldn't help but share how big the moment was for her, as ESPN shared:

Even those making Vinci's travel plans didn't expect such a result from the unseeded challenger. In fact, the Italian was scheduled to fly back home at a time that will conflict with her impending title match.

It's safe to say those will be changed now, as Richard Deitsch of Sports Illustrated noted:

Vinci undoubtedly earned her way to victory, but the overall stats tell a somewhat different story. As noted by Jeff Sackmann of TennisAbstract.com, Williams had the upper hand in one crucial stat:

"

Serena won 52.2% of total points today. That's no guarantee of victory (obviously), but a player who wins 52.2% should win 95% of the time.

— Jeff Sackmann (@tennisabstract) September 11, 2015"

Thanks to a fellow Italian player, Vinci won't have to go through a second top-two seed in consecutive matches in order to win her first major title.

Instead, she'll embark in an all-Italian final with Flavia Pennetta after the No. 26 seed knocked off No. 2 Simona Halep, 6-1, 6-3. The underdog looked like the best player on the court throughout, and it only became more apparent as the final games were played.

At 33, Pennetta became the oldest woman to ever advance to a major final in the Open era and shared her feelings with U.S. Open:

There's no telling what to expect from these two veterans in what figures to be an enticing final that virtually nobody saw coming. Pennetta holds a 5-3 advantage in head-to-head battles, but they're 1-1 on the hard courts.

One thing is certain—the millions of folks who hardly had a thought of an all-Italian final will now have some time to adjust to the changes as well as reassess the shocking results they witnessed Friday.