Ashleigh Barty has overcome a bizarre mid-match stoppage to safely advance to the third round of the US Open for the second straight year.

Barty’s cunning court craft and clutch serve was too much for Lucie Safarova, Australia’s top-ranked player taking out the former French Open finalist 7-5 6-3 under lights on Show Court 17 at Flushing Meadows.

In setting up a likely third-round clash with Spanish superstar Garbine Muguruza, Barty had as much trouble dealing with a malfunction with the on-court PA system as she did with her classy but erratic Czech opponent.

The 18th seeded blasted 10 aces and won 86 per cent of points after landing her first serve while breaking Safarova three times either side of a strange noise disturbance late in the first set.

Play was halted for more than seven minutes as an unnerving sound bellowed through the PA system immediately after Barty was broken while trying to close out the set at 5-3.

The two players – as well as fans in the stands – spent much of the interruption with their fingers in their ears as officials worked frantically to rectify the problem.

“It was very strange. I don’t think Lucie and I have ever come across anything like that before,” a bemused Barty said.

The pair could barely hear the tournament referee trying to explain the seemingly unexplainable during the hold-up.

When play finally resumed, Safarova held to love to draw level at 5-5 only to drop serve in the 12th game with a flurry of unforced errors to hand Barty the first set.

It was one-way traffic in the second as Safarova’s mistake-rate mounted, leaving Barty to prevail on her third match point.

Barty’s victory came on a day of drama and disappointment elsewhere for her compatriots.

Fellow Queenslander Jason Kubler was hospitalised but cleared of a broken ankle after being forced to retire from his second-round men’s match against American Taylor Fritz, while Daria Gavrilova also bowed out.

Chasing a place in the last 32 of a grand slam for the first time, Kubler was trailing 6-3 3-6 6-3 after severely rolling his ankle late in the third set.

Gavrilova was unable to back up her 6-0 6-0 first-round win over Sara Sorribes Tormo, the 25th seed falling 6-1 6-2 to former world No.1 Victoria Azarenka.

-AAP