Smith and countryman Marc Leishman fell two shots shy of American Brooks Koepka in LIV Golf's Singapore tournament on Sunday.
The Australians launched last-round charges at the Sentosa Golf Club but a steely Koepka became the first golfer to win four LIV tournaments.
Koepka, a five-time major winner finished 15 under with Smith and Leishman tied second at 13 under.
Smith's all Australian Ripper GC also including Leishman, Lucas Herbert and Matt Jones won the teams event, taking consecutive titles following their success in Adelaide last weekend.
Smith fired a seven-under 64 featuring eight birdies after an opening round even-par 71 when troubled by a hip injury.
"It was nice to get the hip work done. I was struggling on Friday to be honest," he said.
"My physio did a great job and the last couple of days it has felt awesome."
Brooks Koepka claimed a record fourth LIV Golf title (AP PHOTO)
Smith said his form raises hopes for the May 16-19 US PGA Championship at Kentucky's Valhalla Golf Club, where Koepka will defend his title.
"Couldn't have wanted a better finish heading into a major," he said.
Leishman shot a 66 and with two holes remaining was within one shot of Koepka, who had slept on a three-stroke lead.
But the Australian drove into the trees on his final hole, then hit a branch trying to escape, leading to a bogey.
Koepka closed out victory with a two-under 69, taking his LIV career earnings to more than $A35 million.
Australia's Herbert (five under) and Jones (one under) were off the pace but their collective feats helped propel Ripper GC to successive titles.
The Australians finished 32 under, three shots clear of Sergio Garcia's Fireballs GC and Martin Kaymer's Cleeks GC.
Ripper GC completed back-to-back victories after their win in Adelaide. (Michael Errey/AAP PHOTOS)
"I knew that we had it in us," Ripper skipper Smith said.
"It was just a matter of time.
"There was probably a few lazy boys over Christmas, to be honest, and it took us a little bit to get going.
"But this is how we expect to play and this is how we want to keep playing.
"We just keep pushing each other.
"Herby has been a great addition, obviously, he's got that young blood in him, he wants everyone to do well and he keeps pushing the old boys.
"It's a really good mix of golfers. We've got a really good mix of personalities, and we just gel so well."
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