Australia’s trump card Ashleigh Barty has delivered again, beating top-10 rival Aryna Sabalenka to put Australia 2-1 up in their Fed Cup semi-final against Belarus.

Barty, ranked ninth, absorbed the world No.10 Sabalenka’s best efforts before she cruised to a 6-2 6-2 win in Brisbane.

It came a day after Barty toppled two-time Australian Open champion Victoria Azarenka as Australia hunt a first title since 1974.

Samantha Stosur, who lost a near three-hour tussle to Sabalenka on Saturday, will play Azerenka in the fourth rubber, with a doubles decider to split the countries if scores are locked at 2-2.

Barty proved too steady for the free-wheeling Sabalenka, grinding away on her opponent’s serve until it eventually proved too much for the Belarusian.

Sabalenka’s serving woes of Saturday returned, with six double faults among 16 unforced errors in the first set compared to Barty’s seven.

Conversely, Barty served well in the clutch moments, fending off the early pressure and sealing the first set with an ace.

It was more of the same in the second set as Barty produced in the big moments to save four break points across her first two service games.

Sabalenka was the first to crack when she handed the 22-year-old Barty a break with a loose forehand and double fault for a 3-2 lead.

Barty didn’t need another invitation and she broke Sabalenka again before she served out the match.

Australia’s No.1 walked onto court with three-year-old niece Lucy in her arms to start the day and brought her into the post-game press conference.

With Lucy sitting next to her, Barty credited Stosur for exposing some cracks in Sabalenka’s armour on Saturday.

“I was able to take advantage of it today, particularly on return games,” she said.

“It was a wrestle, it was important to hang in there physically and continue to build pressure.”

Australian captain Alicia Molik resisted the temptation to inject the higher-ranked Daria Gavrilova ahead of Stosur for the fourth rubber given how well the Queenslander struck the ball on Saturday.

That comes despite Stosur taking just three games off Azarenka in their only previous encounter, at last year’s US Open.

-AAP