A 78-75 victory over Brazil has maintained a perfect run for the Australian women's basketball team heading into the London Olympics, but guard Belinda Snell admits it's also given them a much-needed scare.

The gold medal hopefuls looked en route to their first defeat of their pre-Games European tour in France on Saturday, when they squandered a nine-point halftime lead to trail 57-56 at the final break.

Snell almost single-handedly kept the world No.2 Opals in it, with the 31-year-old top scoring with 28 points, including eight from 12 three-pointers.

The close call has put the Opals on alert heading into the London Games, where they are chasing an elusive gold after three consecutive silver medals.

"It was a big eye opener for us," Snell admitted.

World No.6 Brazil entered the match with a point to prove having lost star player Iziane Castro Marques, who was on Saturday dumped from their Olympic campaign for violating a team rule.

"It gave them an opportunity for other players to really step up and they are a team to look out for in London," Snell said.

"They came out and played with a lot of aggression and we were a little bit flat."

The three-point victory puts the Opals one step closer to a dream lead-up to the Games, having won every match so far of their pre-Olympics European tour.

They've beaten France, Great Britain, Angola and China, all by good margins, while Brazil has been their toughest and highest-ranked opponent to date.

Coach Carrie Graf said the victory was vital.

"It was critically important for us to get this win," she said.

"They were more energised than us and played a better game than us.

"But Belinda Snell shot the ball exceptionally and for a dual Olympian to come out and shoot 28 points in a tough game like that, it's fantastic."

The Opals, ranked No.2 behind the United States, play France again on Sunday before their Olympic campaign starts in earnest on July 28 when they take on the home side, GB.

AAP