Marc Leishman turned in 32 to open up a two-shot lead as he chased a dream home victory at the Australian PGA Championship.
Defending champion Cameron Smith entered Sunday at RACV Royal Pines Resort with a three-shot lead but played his first nine holes in one over par and playing partner Leishman took full advantage.
The Australian made four birdies on the front nine to get to 15 under and the lead way from Smith, with England's Ross McGowan at 11 under after breaking the course record with a 63.
Leishman won the first staging of the Nedbank Golf Challenge in the 2016 season and has five wins on the Von Nida Tour but has yet to taste victory on the top tier in his homeland.
Both Smith and Leishman went a long way left off the first tee, with the leader having to take a drop from an unplayable lie in a bush. Leishman did well to find the green and save his par but Smith dropped a shot and the lead was down to two.
Leishman hit a beautiful third into the par-five third to get to 12 under and while Smith made an excellent save to make a par, the lead was just one.
There was then a two-shot swing on the fourth as Leishman chipped in in spectacular fashion and with Smith making another bogey, it was Leishman who led.
The World Number 21 put his tee-shot on the par-three fifth to tap-in range to go two ahead but Smith put an approach to six feet on the next to get back within one.
Leishman drove the green at the par-four eighth and got down in two to lead by two again and he maintained that advantage at the turn.
McGowan won the Madrid Masters in 2009 and nearly made the Ryder Cup Team in 2010 but lost his card in 2011 and despite coming through the Qualifying School in 2015 and 2017, has not kept hold of his playing privileges since.
He birdied the third, fourth, fifth and eighth to turn in 32 and then made four birdies in a row from the tenth to get into double-figures. Another gain came on the 15th and he parred his way home for the course record.
Matthew Millar made birdies at the third, sixth and ninth to sit at ten under, two shots clear of South Korea's Jaewoong Eom.