Defending champions Leander Paes [ Images ] and Martin Damm [ Images ] were knocked out of the US Open [ Images ] while Mahesh Bhupathi [ Images ] and Nenad Zimonjic followed their New Haven triumph with an easy first round victory on Thursday.

• Images: Sania in third round

Fourth seeds Paes-Damm went down 7-6 (1), 3-6, 4-6 to Frenchmen Julien Benneteau [ Images ] and Nicolas Mahut in the opening round.

Meanwhile, Paes' former partner and 10-times Grand Slam champion Mahesh Bhupathi continued a successful summer after starting the year on a low.

Bhupathi-Zimonjic, who won the Pilot Pen tennis Championship last week, disposed the Russian pair of Igor Kunitsyn and Dmitry Tursunov [ Images ] 6-3, 7-5.

The Indo-Serbian duo will face Sam Querrey and Robert Kendrick of America in the second round.

• US Open 2007: Complete Coverage