She's the second Italian in the Open Era to win a major - Francesca Schiavone won the 2010 French Open.
And then, it began - it wasn't just the first all-Italian Grand Slam final in the Open Era...
.@Simona_Halep is 1st into @RogersCup SFs! Beats defending champ Radwanska 0-6, 6-3, 6-1--> http://wtatenn.is/Gp8cGj
Pennetta stormed out to a 4-0 second set lead and would eventually close the match out, 7-6(4), 6-2.
Pennetta and childhood friend Roberta Vinci posed for the traditional photo at net before the match.
And she wasn't the only star at the final - Michael Douglas and Catherine Zeta-Jones were there too.
Photos | WTA Tennis English
1st Grand Slam title! Flavia Pennetta wins #USOpen with 7-6(4), 6-2 victory over Vinci!
Maria Sharapova had a tennis match with David Letterman on the street outside the show's studios in New York #tennis
Mattek wore a hat a during the women's doubles final at the 2005 JP Morgan Chase Open in Carson, Calif. Later this summer, she'd be fined for wearing a similar striped cowboy hat at the U.S. Open.