Flavia Pennetta wins US Open title, retires from tennis

Flavia Pennetta won her first grand slam singles title over Roberta Vinci in an improbable all-Italian US Open final on Saturday then added one more shock to a stunning fortnight by announcing her retirement.

With the 7-6(4) 6-2 win, the 33-year-old Pennetta becomes the fourth oldest grand slam winner in the Open Era and joins 2010 French Open champion Francesca Schiavone as the only Italian women to win a major title.

After embracing childhood friend and Fed Cup team mate Vinci at the net a smiling Pennetta stood at centre court during the trophy presentation and told a capacity crowd at Arthur Ashe Stadium that included Italian Prime Minister Prime Matteo Renzi that she would retire.

"Before I start this tournament one month ago I take a big decision in my life," she said before hoisting the trophy and accepting the $3.3 million winner's check. "This is the way I would like to say goodbye to tennis.

"I'm really happy. It's what all the players seem to want to do, to go out with this big trophy home.

"And so this one was my last match at the U.S. Open and I couldn't think to finish a better way."

Pennetta's surprise announcement provided a jaw-dropping finish to a grand slam packed with surprises.

The final was set up by jaw-dropping upsets as unseeded Vinci knocked off world number one Serena Williams in the semi-finals to end the 33-year-old American's quest for a calendar year Grand Slam.

Pennetta's path to the final included two huge hurdles which she cleared with confidence, taking down Czech fifth seed Petra Kvitova in the quarter-finals and Romanian second seed Simona Halep in the semi-finals.

While the all-Italian final was greeted by a big yawn in the Big Apple, it generated massive interest in Italy with Renzi dropping his busy weekend schedule to fly to New York.

The match between two best friends and former doubles partners who first played each other when they were nine years old got off to a predictably cautious start for two players competing in their first grand slam final.

Showing signs of nerves, Pennetta and Vinci seemed content to battle from the baseline, trading early breaks as the first set went to tiebreak.

After winning the tiebreak Pennetta appeared to sense the title was within her grasp, breaking Vinci at the first opportunity en route to 4-0 lead before clinching the title with a final service break.