There was a huge shakeup at the U.S. Open yesterday when No. 1 ranked Serena Williams lost to Italy’s Roberta Vinci, putting an end to Williams’ epic run of U.S. Open victories and setting up an all-Italy final between Vinci and Flavia Pennetta. Pennetta ended up taking the trophy today and immediately announced her retirement from professional tennis.

Serena Williams tweeted her congratulations to Pennetta today.