NEW YORK (Reuters) - Sara Errani beat her good friend and doubles partner Roberta Vinci 6-2 6-4 on Wednesday to reach the semi-finals of the U.S. Open for the first time.

The two Italians, who teamed up to make it to the doubles semi-finals at Flushing Meadows, briefly put their friendship aside as they traded blows for a place in the last four.

Errani was the favorite after making the French Open final this year and proved too strong for her countrywoman, landing an impressive 85 percent of her first serves to wrap up victory in 72 minutes.

Errani had never made it past the third round of the U.S. Open before this year. She will play either Serena Williams or Ana Ivanovic in Friday's semi-finals.

(Reporting by Julian Linden; Editing by Frank Pingue)