A competitive streak and a level head: Why Ash Barty is the favourite in Melbourne

Already struck by her ability to flick a switch to go from one of the affable players on the tour to one of the most competitive at a moment's notice, Ash Barty's long-time friend and occasional doubles partner Storm Sanders believes the world No. 1 is serving as well as she ever has in the lead in to the 2022 Australian Open.

After taking a break following her third-round exit at the hands of Shelby Rogers in the third round of last year's US Open, Barty returned to the court in style at last week's Adelaide International, romping to triumphant wins in both the women's singles and doubles - alongside Sanders.

Issuing an ominous warning to any potential challenger that stands between her and a maiden Australian Open, Barty's run to that first singles crown of 2022 in the City of Churches included wins over top 20 rivals Sofia Kenin, Iga Swiatek, Coco Gauff and Elena Rybakina.

The 25-year-old then opted to withdraw from the Sydney Tennis Classic and head straight to Melbourne to recuperate following her return to action; rest that will be sorely needed after Thursday's draw threw up a potentially very thorny last 16 meeting with four-time Grand Slam winner Naomi Osaka.

Osaka is seeded 13th in Melbourne after her world ranking fell to 14, following a decision to take a sabbatical to focus on her mental health halfway through last year, and the prospect of a fourth-round meeting between Barty and the defending champion from Japan represents a new and very significant hurdle to Barty's quest to become the first local winner of the Australian Open's women's singles since Chris O'Neil in 1978.

Nonetheless, the possibility of a meeting with the Open's top seed could be said to be just as damaging to Osaka's hopes of going back-to-back - especially with Barty's development of a serve that Jelena Dokic declared to have developed into a new weapon.

"In Adelaide, she looked incredible," Sanders told ESPN. "I watched a lot of her singles matches as well and obviously played doubles with her; she won the singles and we won the doubles and she's looking great.

"She's serving incredibly well. I don't think I've ever seen her serve as well as she has been.

"She's looking really fit and healthy and she's [only] playing singles at the Aussie Open, she's not playing doubles, so you know she's going to have a lot of time to recover between matches."

Sanders credits Barty for her ability to compartmentalise the competitive nature of playing tennis, and disconnect from the rough and tumble when she feels it's necessary, explaining that she doesn't feel the pressure to be 'on' all the time.

"I think she's looking great. She's in a really good mindset as well. We had a lot of fun last week, even in the warm-ups before the matches; I'm sure people are seeing some photos of kicking the footy and doing all these kinds of fun games and stuff," Sanders told ESPN.

"Ash likes to keep it kind of fun and relaxed.

"Hopefully, she can do well here now because obviously it's a home slam and every single Aussie wants to do well - and every single Aussie wants to see her try and take it out.

"But no matter what happens, you know she's gonna give it everything and she'll try our hardest."

Sanders -- a Wimbledon doubles semifinalist in 2021 alongside American Caroline Dolehide -- also partnered with Barty to stage a run to the quarterfinals of the Tokyo Olympics. In Adelaide, the pair dropped just a single set on their way to downing Darija Jurak Schreiber and Andreja Klepac in the final.

Off the court, Sanders describes Barty as a down-to-earth figure whose care and interest in others belies her status as one of the best athletes on the planet - the same type of person she was when they met over a decade ago. But when it's time to get to work...

"She's very competitive," Sanders explained. 'You can see that on the court. She doesn't want to let go of a game. She fights really hard and she's super competitive.

"Even on court in the doubles, sometimes I'm kind of mesmerized by some of the shots she can hit. It's incredible. To her that's kind of normal and I'm kind of trying to play it cool like 'oh, that's just a normal shot' but a lot of the time [internally] I'm like 'wow, I can't believe she just hit that'.

"She's definitely super competitive but yeah, in doubles with me she's super supportive. And sometimes we're not even talking about the doubles, we're talking about, you know, the music that's playing on the change of ends or whatnot.

"But as soon as the timer goes off and the ref calls time and we're back out there you know, she's super focused and yeah, she's completely dialled in - which is an incredible skill to be able to kind of switch on and off like that.

"Under pressure, she's done it in singles; she's able to produce some amazing service and amazing points under pressure, which is a credit to her dialled in mindset."

Barty begins her 2022 Australian Open campaign on Monday evening when she faces Ukrainian qualifier Lesia Tsurenko on Rod Laver Arena.