New York: Novak Djokovic reached the third round of a Grand Slam for the 25th consecutive time while Serena Williams racked up her 80th US Open win as the top seeds eased into the third round on Thursday.

They were joined in the last 32 by 2012 winner Andy Murray and reigning Wimbledon women's champion Petra Kvitova. But former world number one Ana Ivanovic, the eighth seed, and 2011 champion Samantha Stosur were knocked out on a day when stiff winds brought new challenges at Flushing Meadows for players already tackling plus-30 degree heat (+90F).