Serena Beats Venus At The US Open.

Serena Williams overcame her sister Venus at the US Open to move within two victories of her first calendar Grand Slam.

The world number one held her nerve to win 6-2 1-6 6-3 and reach the semi-finals in New York.

Serena, 33, will play unseeded Italian Roberta Vinci in the last four on Thursday.

The American could become the first player to win all four majors in the same year since Steffi Graf in 1988.