Top-ranked Barty advances to second round of US Open

World number one Ash Barty was made to sweat for a 6-1 7-6(7) win over Vera Zvonareva and a spot in the second round of the US Open on Tuesday.

The top-seeded Australian came out firing on all cylinders and raced to a 3-0 lead in a rapid-fire opening set that was over in 24 minutes.

But what looked to be a straightforward afternoon for Barty turned tense in a grinding second set which the 36-year-old Zvonareva forced to a tiebreak before falling 9-7.

Barty has won five tournaments this season, including a second career Grand Slam at Wimbledon and her US Open tune-up in Cincinnati.

In between those two victories, however, the 25-year-old threw in a dismal performance when she was booted out of the opening round of the Tokyo Olympics by 48th-ranked Sara Sorribes Tormo.

Zvonareva is a former US Open and Wimbledon runner-up but her best results came more than a decade ago and the injury-ravaged Russian has had spotty performances at Grand Slams ever since, not advancing past the second round of any major since 2014.

She embraced her moment back on Arthur Ashe Stadium court, refusing to wave the white flag after a lopsided opening set.

In the end Barty's all-court game and power proved too much for her, with the Australian laying down 11 aces and firing 31 winners compared to nine by her opponent.