Serena Williams wasted little time reaching the third round of the US Open with a comfortable victory over Galina Voskoboeva.

The Kazakh, ranked 77th in the world, put up a better fight than the 6-3 6-0 scoreline suggested but it was still nowhere near enough to threaten the world number one.

In her first-round match against Francesca Schiavone, Williams had won the first 10 games and looked on course for a 'double bagel' until the Italian at last managed to win a game.

Voskoboeva must have been more than a little relieved, therefore, when she held serve in the opening game, and she even had a break point for a 3-1 lead.

But Williams saved that, and from there things went downhill for her opponent, who won only one more game in the match.

The games were often close, and Voskoboeva was certainly not afraid to attack Williams, but the American was too solid when it really mattered.

The match had been due to be played on Wednesday but was rained off, meaning Williams will have to come back on Friday for her third-round contest against another Kazakh, Yaroslava Shvedova.

"I'm really pleased with the way I was moving today and moving from defense to offence" - Caroline Wozniacki

Meanwhile. former world number one Caroline Wozniacki raced to a 6-1 6-2 win over South Africa's Chanelle Scheepers to reach the third round.

The sixth-seeded Dane, made to work hard for her first-round victory over Chinese qualifier Duan Yingying, dropped her first service game on Arthur Ashe Stadium court but never looked back in the 67-minute romp.

"I'm really pleased with the way I was moving today and moving from defence to offence," Wozniacki said on-court.

Wozniacki will next play Italy's Camila Giorgi, a 6-4 7-6 (8) winner over Hsieh Su-Wei of Taiwan.