Fourth seed Agnieszka Radwanska knocked out by Peng Shuai in US Open second round

Peng Shuai has dumped women's fourth seed Agnieszka Radwanska out of the US Open in the second round.

The world number 50 came through in straight sets 6-3 6-4 on Louis Armstrong Stadium to continue Radwanska's poor record at Flushing Meadows.

The Pole has never got past the fourth round in New York, but got off to a good start today.

She broke China's Peng in the opening game and then consolidated the advantage to go 2-0 in front.

That would be her only break of serve, though, and Peng won six of the next seven games to clinch the opener.

A break midway through the second set was enough for Peng and she will now face either Italy's Roberta Vinci or Irina-Camelia Begu in round three.