The stage is set for the 2015 U.S. Open women's final and it will not feature the best woman player Serena Williams as Roberta Vinci takes on Flavia Pennetta this Saturday at the Arthur Ashe Stadium. 

Vinci, who is ranked 43rd in the world, surprised everyone when she spoiled Williams' attempt of having a perfect Grand Slam year in the semifinal of the U.S. Open. 

The 32-year-old Italian defeated Williams 2–6 6–4 6–4 to have a chance of capturing her first Grand Slam title. 

"It was an incredible match. 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," Vinci said, according to BBC Sports. 

Meanwhile, Williams said in a conference that she does not want to talk about how disappointing the semifinal result is and added that from the beginning there was no pressure for her to win. 

Following the match, Vinci apologized to the American people, Williams, and the Grand Slam saying that it was her day.

Meanwhile, world number 26 Pennetta, also ousted a top-seeded opponent in the second best woman player in the world Simona Halep in the semifinal to set up a meeting with her fellow Italian Vinci. 

Pennetta disposed Halep in straight sets 6–3 6–1 and will look to continue with her consistent performance since she only dropped two sets so far in the tournament, according to the International Business Times.

The final appearance this Saturday at the 2015 U.S. Open is also the first for the 33-year-old tennis player in a Grand Slam tournament. 

"It means everything to me. I didn't think I would get so far in the tournament. I thought I played really well. Nothing changed. I just tried to play my best every match, not think about the draw, so here I am and really happy. Grazie mille, grazie tutti," Pennetta said, according to The Guardian. 

The match will take place on Saturday, Sept. 12, at 3 p.m. EST. To watch via live stream, click here.