Ashleigh Barty is two victories away from becoming the Australian Open's first home-grown winner in 42 years, but the top seed must first tame aggressive American Sofia Kenin on Thursday.

The other-semi final at the Australian Open in Melbourne, where temperatures are forecast to soar to nearly 40 degrees Celsius (104 Fahrenheit), tees up Wimbledon champion Simona Halep and unseeded Garbine Muguruza.

The 23-year-old Barty is the only Australian left in the men's or women's draw and will be expected to beat Kenin, the 14th seed contesting her first Grand Slam semi-final. Barty, into the semi-finals at the Australian Open for the first time, has defeated the American in four of their five previous meetings.

Excitement is growing that Barty can become the first Australian winner since Chris O'Neil in 1978. But the world number one and reigning French Open champion is trying to ignore the hype. "I don't pay attention to it, honestly. I'm here to try and do the best that I can," she said, after defeating Czech seventh seed Petra Kvitova in the quarter-finals. "Obviously it's exciting. Hopefully I can bring a smile to a few faces around our country and around the world."

Underdog Kenin, 21, is flying the flag for the United States as the only American left at the Australian Open.

Born in Moscow but a fiercely proud American -- her racquet is in the colours of the stars and stripes -- Kenin is adamant she will not shrink in the face of what will be vocal home support for Barty. "I guess I could just say aggressive, the fight in me," she said, asked what her strengths are. Kenin defeated the 15-year-old sensation Coco Gauff on the way to the last four.

Romania's Halep, defeated in the 2018 final by Caroline Wozniacki, is hitting top form at the right moment. She is yet to drop a set in Melbourne as she chases a third Grand Slam title, having triumphed at Roland Garros in 2018 and defeated Serena Williams 6-2, 6-2 to win Wimbledon last year.

"Perfection doesn't exist, but I'm very happy with the way I played," Halep said after disposing of 28th-seeded Estonian Anett Kontaveit 6-1, 6-1 in her quarter-final on Wednesday. "I felt great on court, I was moving great, I felt the ball really, really good."

But in Muguruza, Halep takes on a player with Grand Slam pedigree whose confidence is also soaring. Like Halep, Muguruza is a former world number one and winner at Roland Garros and Wimbledon.

Unlike Halep, the 26-year-old Spaniard failed to kick on after those two Grand Slam triumphs. Muguruza ended a wretched 2019 ranked 36 in the world -- the first time since 2014 that she finished the year outside the top 20.

She spent the off-season climbing Mount Kilimanjaro to clear her head of tennis and reunited with coach Conchita Martinez. The results have been almost immediate, defeating top-10 seeds Kiki Bertens and Elina Svitolina on the way to the semi-finals, having started the tournament with a viral illness.

"I think the toughest moment is when you work hard, work like before, or even harder, and you don't feel like results are coming fast," said Muguruza, reflecting on a couple of poor years by her high standards. "Athletes sometimes can get a little bit desperate, get too impatient about it. It's very tough to be for so many years in the top of the game, being that consistent."