Perth - Kristina Mladenovic proved a class above nervous Fed Cup debutant Ajla Tomljanovic to overpower the Australian and give France the first point in the final at Perth on Saturday.
The French world No 40 crushed the 51st-ranked Tomljanovic 6-1, 6-1 in 71 minutes, inching her country closer to a third title and first since 2003.
World No 1 Ashleigh Barty faces Caroline Garcia in Saturday's second singles rubber to try to draw the match level.
"I think she played good but I just came out there and basically wanted to win," said Mladenovic in her courtside interview.
"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."
Australian captain Alicia Molik opted for Tomljanovic to play singles ahead of veteran Samantha Stosur, but the gamble spectacularly backfired, denting their chances of an eighth title and first since 1974.
The 26-year-old did not hit a single winner in the opening set, played in scorching heat but with the roof open at Perth Arena.
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 did not last long with the French number one's powerful forehand proving too hot to handle.
She kept the momentum going in the second set as Tomljanovic wilted under the pressure, again galloping to a 5-0 lead before the Australian finally won a game only for Mladenovic to comfortably serve out the match.
Tomljanovic is also scheduled to play the reverse singles on Sunday against Garcia, but this may change after her mauling by Mladenovic with Molik having the option to switch to the more experienced Stosur.
Results from the Fed Cup final between Australia and France at Perth Arena on Saturday:
Australia 0 France 1
Kristina Mladenovic (FRA) bt Ajla Tomljanovic (AUS) 6-1, 6-1
Ashleigh Barty (AUS) v Caroline Garcia (FRA)
Sunday (from 05:00 SA time)
Ashleigh Barty (AUS) v Kristina Mladenovic (FRA)
Ajla Tomljanovic (AUS) v Caroline Garcia (FRA)
Samantha Stosur/Ashleigh Barty (AUS) v Caroline Garcia/Kristina Mladenovic