Ivanovic shines in win

Former world number one Ana Ivanovic took another step forward in her recent renaissance when she beat 21st seed Zheng Jie 6-3 6-0 to reach the third round of the US Open.

The Serbian, who topped the rankings just two years ago, smashed 22 winners en route to an impressive victory in just 56 minutes on a hot Arthur Ashe Stadium court.

Ivanovic was beaten in the first round in New York last year but has been slowly making her way back up the rankings and was far too strong for Zheng.

Zheng had no answer to Ivanovic's power and after taking the first set, the Serb raced through the second to set up a clash with either 13th seed Marion Bartoli or another Frenchwoman Virginie Razzano.

Number ten seed Victoria Azarenka collapsed on court in the searing heat during her second-round match against Gisela Dulko.

Azarenka slumped to the ground while 1-5 15-30 down on the Grandstand court and, after receiving medical treatment, was taken off in a wheelchair. It lead to gasps from the crowd and forced her retirement from the tournament.