Top seed Iga Swiatek breezed into the third round of the US Open with an emphatic win over Japanese qualifier Ena Shibahara.

The five-time major winner dropped just one game against Shibahara, who managed to hold serve early in the second set to avoid a dreaded 'double bagel'.

Swiatek, 23, didn't face a single break point as she wrapped up the 6-0 6-1 victory in 65 minutes.

Former Wimbledon champion Elena Rybakina withdrew from her second-round match against France's Jessika Ponchet because of "injuries", handing the world number 143 a walkover.

"I did not want to finish the last Grand Slam of the year this way but I have to listen to my body, and I hope I can close out the remainder of the year strong," Rybakina, the fourth seed, said in a statement.

Earlier, Italy's fifth seed Jasmine Paolini progressed after Karolina Pliskova retired just three points into their second-round encounter.

The 2016 runner-up was 30-15 down in the first game when she pulled up injured.

Czech Pliskova requested medical treatment for her foot, but was unable to continue and limped off Louis Armstrong Stadium.

Paolini, a finalist at this year's French Open and Wimbledon, will face Kazakhstan's Yulia Putintseva next.