BRISBANE (AFP) - Australia powered into their first Fed Cup tennis final since 1993 on Sunday (April 21), with Ashleigh Barty and Samantha Stosur clinching the deciding fifth rubber in Brisbane against Belarusian pair Victoria Azarenka and Aryna Sabalenka.

Their battling 7-5, 3-6, 6-2 win set up a title match against either France or Romania in November.

The tie was sent into the crucial doubles match after Azarenka crushed Stosur 6-1, 6-1 in the reverse singles, following Barty sweeping past Sabalenka 6-2, 6-2.

Belarus, the losing finalists in 2017, was scheduled to pit Lidziya Marozava and Vera Lapko against the Australian duo, who were playing together for the first time. But with so much on the line team captain Tatiana Poutchek opted instead for the more accomplished pairing.

But they fell short to give seven-time champions Australia a crack at their first title since last winning in 1974.

"I could not have picked two more perfect athletes to compete. Ash and Sam are superstars," said elated Australian captain Alicia Molik.

Barty called making the final "unbelievable" while Stosur said it was "super exciting".

"We knew it was going to be a tough one and we just so happy with how we played," added Stosur. "All the girls have worked so hard throughout the year and we really stick together."

Watched on Pat Rafter Arena by Evonne Goolagong, who led Australia to that last Fed Cup win, the home duo grabbed an early break against Sabalenka's serve in the opening game.

Belarus evened it up in the sixth game and they exchanged breaks again before the Australians attacked Azarenka's serve to break and go 6-5 in front, with Stosur securing the set with an overhead smash.

The second set went with serve until a powerful Sabalenka forehand off Stosur's serve gave Belarus the edge and Sabalenka served out the set to take the tie to the wire.

A net volley from Stosur gave Australia the crucial advantage off the Azarenka serve in the fourth game of the deciding set and they held their nerve for a famous victory.

'Very focused'

Earlier, ice-cool world No. 9 Barty produced a commanding performance to beat Sabalenka, ranked one place below her.

She got a break in the fifth game of the first set, when the Belarusian fired down four double faults, including on break point. Sabalenka's serving wobbles continued with Barty exploiting the weakness to take the set.

A tight second set also went with serve until the fifth game, and in a mirror image of the first Barty again broke when Sabalenka double faulted as the pressure mounted and sealed the match with an ace.

"A really clean match today. I stuck to my game plan well and was able to execute under pressure," said Barty, who is now on a 13-match Fed Cup winning streak.

Former US Open champion Stosur has often struggled on home soil, although success has not been completely elusive. On her last appearance Down Under in January she won the women's doubles title at the Australian Open.

But the nerves were fluttering in her singles match against two-time Australian Open winner Azarenka, who quickly took charge, racing to 4-1 lead.

Stosur fired down seven double faults as Azarenka won the set in just 29 minutes and the second followed a similar pattern.

"It was about either we stay and fight for another match or go home," said Azarenka. "So I was very focused."