Italy's Roberta Vinci caused a huge shock as she beat Serena Williams at the US Open to end the American's hopes of a calendar Grand Slam.

Vinci, the world number 43 and playing her first Grand Slam semi-final, won 2-6 6-4 6-4 in New York.

Williams, 33, had been two wins from completing a clean sweep of all four majors in 2015.

Vinci, 32, will play Flavia Pennetta in an all-Italian final at Flushing Meadows on Saturday.

More soon.

Unseeded Roberta Vinci makes it into her first Grand Slam final

Roberta Vinci will play country-woman Flavia Pennetta in the final - the first US Open final to be contested by two Italian players

Serena Williams' calendar Grand Slam dreams come to an end