World Number 43 Roberta Vinci defeated Top seed Serena Williams in three sets to reach her first Grand Slam Final.
Serena Williams's hopes of securing a calendar Grand Slam were ended in stunning fashion by Italy's Roberta Vinci in the US Open semi-finals.
Vinci, caused a huge upset with a 2-6 6-4 6-4 win.
Vinci, 32, will play Flavia Pennetta in an all-Italian final at Flushing Meadows on Saturday.
Pennetta, the 26th seed, outplayed Romanian second seed Simona Halep in the first semi-final to win 6-1 6-3.