MELBOURNE, Australia — It is all about choices, this game of tennis and life.

Down-the-line or crosscourt? Rip or chip? Stay home and rebuild your strength? Or hit the road in search of more points and glory?

The coronavirus pandemic that disrupted old patterns and created new problems has made some of the choices more complicated, but Ashleigh Barty is on a hot streak, as anyone who has played her in this Australian Open can confirm.

Madison Keys was the latest to swing away and come up short as Barty kept delivering pitches and tactical shifts that Keys could not handle. Barty won the first set of their semifinal on Thursday night in 26 minutes and won the match in just over an hour, 6-1, 6-3.

She is the first Australian since Wendy Turnbull in 1980 to reach the women’s singles final at the Australian Open.

She will face Danielle Collins of the United States, who defeated Iga Swiatek of Poland, 6-4, 6-1, in the second women’s semifinal. Barty will be the favorite based on her cool and precision under pressure over the last 11 days. Barty said she intended to embrace the opportunity rather than try to block out its significance.

“You have to,” Barty said. “It’s fun. It’s brilliant to be playing in the business end of your home slam. I’m not going to lie about that. It’s amazing. I think being able to experience it multiple times has been incredible, but Saturday’s going to be a new experience for me. So I go out there and embrace it, smile, try and do the best that I can and whatever happens, happens.”

Collins is one of the most ferocious competitors in women’s tennis and has been serving and returning particularly well down the stretch in Melbourne. She won 86 percent of the points against Swiatek’s second serve on Thursday.

“She loves to get in your face and loves to really take it on,” Barty said.

Barty leads their head-to-head series 3-1, but Collins won their most recent match in straight sets in Adelaide, Australia, last year, and has also pushed her to three sets in two of their other matches.

“We’ve had some incredible battles over the years,” said Collins, the No. 27 seed. “To play against the No. 1 player in the world in her home country, I think it’s going to be really spectacular. I love the energy the fans bring whether they are for me or for my opponent.”

Collins, 28, is a two-time N.C.A.A. singles champion from the University of Virginia who turned professional later than most of her rivals on the professional tour. She is a scrappy, demonstrative player but also has point-ending power and has come back convincingly in the last nine months after struggling with endometriosis. Since July, she has a 32-7 singles record and will rise to No. 10 in the rankings on Monday, becoming the top-ranked American.

Collins has battled some more in Melbourne with tough three-set victories over Clara Tauson in the third round and Elise Mertens in the fourth round. Barty has yet to come close to dropping a set, and Keys met Barty at the net after Thursday’s rout with a smile on her face as if to say, “You’re in the zone, Ash, enjoy it.”

“She’s just playing incredibly well. I mean, you have a game plan in your head, but she’s just executing everything so well,” Keys said in her post-match news conference. “She’s serving incredibly well, so you don’t get any free points on that. Her slice is coming in so much lower and deeper than it was in the past so it’s hard to do anything on that. Then you try to play to her forehand and she can open you up there.”

Barty’s variety is her strength, and as the match with Keys developed, she rarely gave the powerful American the same type of shot for long, mixing two-handed backhand drives with one-hand slices, off-speed angled forehands with bolts up the line.

“I think everything has just improved a little bit,” Keys said. “I think she’s got a little bit more precise on her serve. I think her forehand she’s doing a really good job at mixing up paces and spins, as well. It feels like you can’t really get in a rhythm off of that forehand side. Then on her backhand side, I mean, everything is coming in at your shoelaces on the baseline. So it’s not like you can really do anything with that.”

Keys, who was on a 10-match winning streak, looked more resigned than glum.

Tennis may not mean as much to Australia, as it once did in the days of Rod Laver, Ken Rosewall, Margaret Court and Evonne Goolagong Cawley. But a Barty victory in Australia would certainly be a cultural happening. The 25-year-old from Brisbane is a particularly popular figure here with her down-to-earth personality and deep roots in the land: she is partly of Indigenous heritage.

Ranked No. 1, she won her first Grand Slam singles title at the 2019 French Open and her next at last year’s Wimbledon, prevailing in a mood-swinging final against Karolina Pliskova that got complicated before she won in three sets.

But there have been no edgy matches or extended challenges so far in Melbourne, where she can become the first Australian to win the singles title since Chris O’Neil in 1978.

O’Neil was unseeded and ranked outside the top 100: one of the biggest surprise Grand Slam champions in tennis’s long history. Barty is in a very different position as the top-ranked player in the game and the focus of attention in her country whenever she plays a match.

But after choosing to cut her season short in 2021 and return home to Australia to recover after the U.S. Open where she was upset in the third round, she has started the 2022 season fresh, focused and devastatingly on target. She has dropped just 21 games in six matches and is striking a fine balance between finesse and power.

Next challenge: her first Australian Open singles final on Saturday night in prime-time in Rod Laver Arena. Is she ready?

“Absolutely,” she said after steam-rolling the unseeded Keys. “Let’s do it.”