Jordan Zunic saw his lead cut to one shot as the Australian PGA Championship was set for a tense finish at RACV Royal Pines Resort.
A brilliant 64 in round three had put the Australian three shots ahead and while he turned in 34 to get to 19 under, countryman Cameron Smith played his first nine holes in four under to slash the lead.
Adam Bland was then at 16 under, three shots clear of another Australian in David Bransdon.
Zunic recorded his best European Tour finish here with a tie for ninth in the 2016 campaign but tallied just one top ten in eight events on the Challenge Tour last season.
The 25 year old has credited his improvement this week to making advances in his mental game with the help of veteran Australian Nick O'Hern and he would need all his mental strength down the stretch in Queensland.
Zunic had the chance to shoot a 59 on Saturday before finishing his round bogey, double-bogey and his poor run continued as he dropped a shot on the first.
Bland picked up a birdie from five feet on the same hole to sit just two off the lead and when Smith three-putted the par three second, the 35 year old was alone as Zunic's nearest challenger.
Smith bounced back with a birdie as he nearly holed out for eagle on the par five next but Zunic also took advantage for the third day in a row and the lead was back to three.
Both of the leading duo then birdied the fourth, with Smith following Zunic in after he holed an 18-foot left-to-righter down the hill.
When they put their tee-shots on the sixth within ten feet for another pair of birdies, it was looking like a two-horse race with Bland making five pars in a row.
A Bland birdie on the seventh kept him within touching distance but Smith also made a gain from five feet to cut the lead to two.
Bland made it two birdies in a row on the eighth to get to 16 under but Smith produced the fireworks, driving into the water then hitting the pin and seeing his ball bounce a long way from the flag before draining the monster putt for par.
He then birdied the ninth for the fourth day in a row to cut the gap to one shot.
Bransdon turned in 33 to sit a shot ahead of Marc Leishman and two clear of Lucas Herbert as Australians locked out the top six on the leaderboard.
Defending champion Harold Varner III was ten under after 12 holes to sit alongside Nathan Kimsey who was enjoying an excellent final round.
The Englishman - who won the Qualifying School in 2016 but lost his card in his rookie campaign - was seven under for his round with two play, a shot ahead of Masters Tournament champion Sergio Garcia, last week's winner Wade Ormsby, Dane Joachim B Hansen and Australian Jake McLeod.