Cashing in on preferred lies from the soggy fairways, Herbert iced his opening round with an eagle three at the last to card an eight-under-par 63 at Victoria Golf Club on Thursday.
The newly crowned NSW Open winner grabbed a one-stroke lead over 2023 Japanese amateur champion Rintaro Nakano and American Ryggs Johnston.
Nakano and Johnston both posted seven-under 65s at neighbouring Kingston Heath to be tied for second, one shot ahead of a smarting Smith, who signed for an eventful six-under 65 at Victoria.
Smith had lashed officials after Wednesday's pro-am for setting up Kingston Heath for American-style target golf, lamenting the "bullshit" softening up of the traditional hard and fast sand-belt layout.
Australian Cameron Smith had an eventful first round at the Victoria Golf Club. (Con Chronis/AAP PHOTOS)
After dropping a shot on his third hole of the morning, the 2022 British Open champion fired up to take out his frustration with officials in a spectacular run of six successive birdies mid-round.
After starting his round on the 10th, Smith conjured a brilliant momentum-saving par from behind a tree on the sixth before closing with his eighth and ninth birdies of the day.
"Yeah, pretty solid. I didn't do really much wrong today," Smith said.
"It was a bit of a slow start, obviously. Getting up so early, just a bit drained there at the start and then I finally woke up.
"The coffee worked and I got on a good roll there through the turn.
"The course is definitely gettable. The greens are soft and there wasn't much wind out there this morning."
The pre-tournament favourite now has three rounds to attack Kingston Heath as he bids to etch his name on the Stonehaven Cup for the first time.
Smith, though, will have to catch an in-form Herbert.
Two weeks after reeling in a four-shot final-round deficit to deny Smith the NSW Open trophy on the Murray River, Herbert is again threatening to crash his Ripper skipper's party.
The 28-year-old produced a bogey-free round featuring six birdies and his eagle at the ninth, after Herbert also started from the 10th on Thursday.
Ominously for his chasers, Herbert thought he could have shot even lower.
"There were a lot of shots left out there. You probably feel like that with every round of golf to be fair," he said.
"I didn't really think I'd holed that many putts, just hit it quite nicely, got it into the right spots.
"I probably got a couple of lucky breaks here and there where shots that maybe weren't the best didn't get punished the way they could have.
"You've just got to take your luck when you get it. There's days when you can play really well and nothing goes for you."
While Herbert and Smith ran hot, former world No.2 Minjee Lee's hopes of also winning a maiden Open trophy in the women's event suffered a setback with a first-round two-over 74 at Victoria.
Minjee Lee has her work cut out after a two-over first round at the Australian Open. (Con Chronis/AAP PHOTOS)
Lee found herself eight shots adrift of her LPGA Tour peer Su Oh after Thursday morning's wave of finishers.
The two-time major winner battled an unco-operative putter all round, racking up six bogeys to be left staring down her first winless year since the COVID 19-ravaged 2020 season.
Oh mixed eight birdies with two bogeys in her six-under 66 at Kingston Heath.
Women's title favourite Hannah Green and Lee's brother Min Woo were among the stars with afternoon tee times on Thursday.
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