Leishman shot a bogey-free six-under 66 in Thursday's first round at the Grange in Adelaide to share the lead with American megastar Bryson DeChambeau.
DeChambeau's fellow major winners Dustin Johnson, who landed two eagles in his five under, and Jon Rahm (four under) lurk ominously.
"The good thing about LIV is you're playing against those guys every week," Leishman said.
"So whether you're ahead of them or you're chasing them, you know you have to play really good golf to win one of these (tournaments).
"That's certainly going to be the case this week for whoever goes out and wins it or comes from behind or whatever that is - hopefully it's me."
Leishman entered the opening round in the shadows of his compatriots Cam Smith and the emerging Elvis Smylie, who won on his LIV debut last weekend in Saudi Arabia.
Smith, after carding bogeys on his initial three holes, fought back to finish even par, while the 23-year-old Smylie shot three birdies in his two-under 70.
Fellow Australian and Ripper GC teammate Lucas Herbert finished one under after a rollercoaster round featuring three bogeys and four birdies.
Leishman had no such dramas in a superb start to the fourth edition of LIV's Adelaide tournament which is yet to feature an Australian individual winner.
"An Australian winning here would be massive ... I hope we find out this week," Leishman said.
"I have seen Aussies win Australian Opens and PGAs, and I won a Victorian PGA last year.
"I've never seen an Australian win an individual title in Australia at a LIV event, which I think would be pretty special.
"Obviously I was a part of the (Ripper GC) team win in 2024 in Adelaide and that felt like winning a major for me.
"An Australian winning here would be massive."
The 42-year-old peeled off four birdies in a seven-hole stretch at the sandbelt course in Adelaide's beachside western suburbs.
And Leishman, chasing a second victory on the LIV circuit to follow his triumph in Miami last year, banked two more birdies on successive holes, the 16th and 17th.
His six-under effort was one stroke shy of his best LIV round in Adelaide - he twice shot seven under at the Grange, in 2023 and '24.
Another Australian in the field, Adelaide's Wade Ormsby, who is a LIV reserve and was summoned to replace Phil Mickelson who remains in the US because of family matter, finished one over on his home course.
Anthony Kim shares second place at five under, a shot ahead of  Abraham Ancer and Northern Ireland's Graham McDowell who both banked rounds of 68.
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