Australia's last French Open winner Margaret Court said Sam Stosur had boosted the country's flagging tennis fortunes after her surprise run to the Roland Garros final.

Court hailed Stosur's fitness and mental toughness in beating multiple Grand Slam winners Justine Henin and Serena Williams, and former no.1 Jelena Jankovic, to stand one win from the title.

The former champion, who won 62 Grand Slam singles and doubles tournaments, said the powerful Stosur's achievement was important for Australian tennis, which has been in a lean period since Lleyton Hewitt's 2002 Wimbledon win.

"Sam is doing so well for herself and it is wonderful to see, but she's also doing a great thing for tennis in Australia," Court said.

"I watched her match against Serena and the way she kept her nerve was fantastic. She played really well, although I think her win over Justine was even better because Justine is so accomplished on clay."

Stosur will face Italy's Francesco Schiavone today, when she is favourite to become the first Australian woman to win a major since Evonne Goolagong at Wimbledon in 1980.

"It's great for women's tennis in this nation, all tennis in Australia," said Court, who won her last French title in 1973.

Australian bookmakers had already installed Stosur, 26, as the title favourite after her shock quarter-final win over Williams.

Stosur broke into the top 10 in March and has climbed to a career-high seventh ranking.