Louis Oosthuizen saw his lead cut to one shot in the early stages of the final round of the ISPS HANDA Perth International.
The South African fired rounds of 64-67 on Friday and Saturday at Lake Karrinyup Country Club to open up a three-shot lead but had led by five before two late bogeys in round three stalled his momentum.
Another dropped shot on the second made it three in five holes and all of a sudden he led by a single stroke from Jason Scrivener, Peter Uihlein and Romain Wattel.
A win today would be Oosthuizen's first European Tour victory in just over two years and continue a remarkable start to the season for South Africans, who have so far won five of the ten events.
Home favourite Scrivener picked up a birdie on the first after an impressive pitch left him a short putt and that soon had him within two of the lead as Oosthuizen left his second short at the second.
Frenchman Wattel also dropped a shot at the second and when Scrivener took advantage of the par five third, the lead was down to a single shot.
Oosthuizen's start was nervy, and he put his third on the third through the back of the green but pulled out a fairway wood and hit the pin to rescue a par.
Wattel, meanwhile, hit the green in two and holed a lengthy putt for eagle to join Scrivener at 13 under, where Uihlein soon found himself courtesy of a birdie on the fourth.
France's Grégory Bourdy and Australian Marcus Fraser were then at 11 under, with Julien Quesne and Brett Rumford four shots off the lead.