Australian Ash Barty has continued her brilliant season, advancing to the third round of the US Open with a straight sets win over Aliaksandra Sasnovich.

Barty wrapped up the match 6-1, 7-6 in one hour and 21 minutes to set up a tough third round match with American Sloane Stephens, who defeated Donika Cubulkova in three sets on Thursday morning AEST.

Barty hit nine winner's to Sasnovich's one in the first set and five aces to nil, as she stamped her authority on the match.

Sasnovich fought hard in the second, taking it to a tiebreak, with Barty winning 9-7 in the breaker.