World number one Serena Williams has brushed aside Yaroslava Shvedova to reach the fourth round of the US Open.

The 16-time Grand Slam champion, who is bidding for a fifth title in New York, was in merciless form as she completed a 6-3 6-1 victory in the final match of day five at Flushing Meadows.

Williams broke for a 4-2 lead and went on to serve it out in 38 minutes.

Shvedova was powerless to resist the American's serve, which was firing on all cylinders after she went up an early break in the second.

Another break to go 4-1 up all but extinguished any hope that the Russian had of mounting a comeback.

Williams will face her Australian Open conqueror Sloane Stephens in the next round.