Flavia Pennetta defeats Roberta Vinci, wins 2015 U.S. Open title

During the trophy ceremony, Pennetta announced she would retire from tennis.

Flavia Pennetta earned her first Grand Slam title with a 7-6(4), 6-2 victory over Roberta Vinci in the U.S. Open final. 

Pennetta and Vinci improbably reached the final after upsetting No. 2 SimonaHalep and No. 1 Serena Williams, respectively, in the semifinals. The final marked the first all-Italian final in Grand Slam history. 

Serena Williams finally buckles under pressure in final leg of Grand Slam bid

​​After a close first set was decided in a tiebreaker, Pennetta pulled away in the second set by converting three of four break point opportunities. Pennetta, 33, had only made it past the quarterfinals of a Grand Slam once prior to this tournament, at the 2013 U.S. Open. 

Pennetta was exceptional at the net, winning 16 of 20 net points. The tournament's No. 26 seed also recorded 28 winners. 

During the trophy ceremony, Pennetta announced that she would be retiring from tennis. She said that she made her decision before the tournament started. 

"This is the way I would like to say goodbye to tennis," Pennetta said at the ceremony. 

She later added: “This it the perfect moment, I think. Was a really hard decision to make, but I'm really happy that I did it. I'm really happy and proud of myself.”

Pennetta said she will compete through the end of the year. 

Vinci's runner-up finish is her best in a Grand Slam singles event. Previously, her best performance at a Slam was a quarterfinals appearance at both the 2012 and 2013 U.S. Opens. 

“It's strange. I didn't expect this,” Vinci said of playing in her first Grand Slam final. “I'm so happy that I reach the final. Against Flavia is strange, but I'm really happy even when I lost.”

After the match, Serena Williams offered her congratulations to Pennetta on Twitter. 

@flavia_pennetta congrats I'm so happy you won. You deserved it. I am also happy for the rest of your life's journey. I will miss your smile

— Serena Williams (@serenawilliams) September 12, 2015

Pennetta said she made the decision to retire in Toronto last month, and that she didn't expect to announce her retirement as a U.S. Open champion. 

“With this, winning today,” Pennetta said, smiling, ”my life is perfect.”

• Watch Roberta Vinci's interview after Serena upset