Talor Gooch doesn't want to look like an idiot and choke on a 10-shot lead in the final round of LIV Golf's Australian debut.

The American has tamed the Grange in Adelaide with consecutive 10-under 62s - the $5.97 million winner's cheque is his to lose.

"You don't want to look like an idiot in front of a bunch of people, plain and simple," Gooch told reporters on Saturday.

"Whenever you're doing something that you've worked your whole life for, you're going to get nervous.

"I'll definitely be nervous tomorrow, throughout."

The 31-year-old is 10 strokes clear of a half-dozen players including fellow American Brooks Koepka, whose seven-under 65 on Saturday was blemish-free.

More major winners, Australia's Cam Smith and American Phil Mickelson, are a shot further back at nine under.

Smith knows he could shoot the proverbial lights out on Sunday and still fall short of the runaway leader.

"Talor is playing some really good golf at the moment," Smith said after signing for a six-under 66.

"He would have to help us out a little bit which I don't really wish on anyone."

Nevertheless, Smith was plotting a last-ditch assault.

"I feel as though I've got the place pretty sorted in regards to how to play it," he said.

"There is a really low number out there."

Mickelson, in his seven-under 65 featuring eight birdies, was feted every step by a sell-out 35,000-strong crowd at the sandbelt course in Adelaide's west.

"I didn't really understand fully how many people were going to be out here," he told reporters.

"What I am appreciative of is how kind everybody has been and how the comments have been fun or funny and positive.

"It has been fun to play in this environment.

"It makes you want come out and be a part of it and do more for the fans ... be more engaging.

"It helps break down the barrier between player and fans and brings them closer together."

Smith's all-Australian Ripper GC is in last place of the 12 teams - with each quartet's three best scores counting towards their total.

Smith's teammates Marc Leishman (four under), Matt Jones (one over) and Jed Morgan (three over) are also battling to make individual inroads.

Gooch's Rangegoats GC - with fellow Americans Harold Varner (nine under) and Bubba Watson (seven under) - top the team standings at 36 under.

They're three shots clear of the Louis Oosthuizen captained Stingers GC.