World number one Ashleigh Barty emphatically hauled Australia back into contention in the Fed Cup final on Saturday, crushing Caroline Garcia 6-0, 6-0 after France's Kristina Mladenovic whipped her teammate Ajla Tomljanovic.

Barty, fresh from winning the WTA Finals in China, came on court in Perth under pressure after the nervous Tomljanovic was thrashed 6-1, 6-1 in her tournament debut.

But in searing 38 Celsius heat she kept her cool to embarrass a stunned Caroline Garcia in a rare double bagel, with the Frenchwoman having no answers to the Barty armoury in front of 13,000 fans.

It left the tie evenly poised at 1-1 ahead of Sunday's reverse singles and a doubles clash if needed, with Australia targeting an eighth title and first in 45 years, while France are seeking a third, their first since 2003.

"This is remarkable, I couldn't have asked for a better match," said Barty in her courtside interview.

"I'm so happy to be back here in Perth. I started my year off here and it's a hell of a way to finish it off."

The French Open champion, wrapping up a breakthrough season, was imperious, firing down pinpoint first serves and effortlessly pushing Garcia around the court, forcing errors.

She set the tone by breaking Garcia's first service game and there was no way back for a player who was once ranked four in the world but has slipped to 45.

Barty wrapped up the first set in 29 minutes and there was no let up as she sent down 11 forehand and four backhand winners.

The ease of her win was a huge relief for Australian captain Alicia Molik, whose gamble to play Tomljanovic in singles ahead of veteran Samantha Stosur spectacularly backfired.

Tomljanovic is scheduled to play again on Sunday, but given her performance Molik may change her mind and revert to Stosur — Australia's most successful ever singles player, spanning 16 years of Fed Cup action.

France captain Julien Benneteau faces a similar dilemma with Garcia. His other options are Alize Cornet, Fiona Ferro or Pauline Parmentier.

Currently Barty and Stosur are down to play Mladenovic and Garcia in what could be a doubles decider.

World number 40 Mladenovic gave her country a 1-0 lead by destroying Tomljanovic in 71 minutes.

"I think she played good but I just came out there and basically wanted to win," said Mladenovic after clinching her 22nd career Fed Cup win.

"I really did almost the perfect match, I was really in the zone. I love these sort of matches, the bigger the pressure, the more special the event."

Tomljanovic failed to hit a single winner in the opening set. She was broken in the first game and Mladenovic quickly turned the screws, racing to a 3-0 lead before a double-fault on break-point in game four allowed Tomljanovic a rare glimmer of hope.

But it didn't last long with Mladenovic's powerful forehand proving too hot to handle.

She kept the momentum going in the second set as Tomljanovic wilted under the pressure, galloping to a 5-0 lead before the Australian finally won a game only for Mladenovic to comfortably serve out the match.