Adam Scott has warned Australian Open title hopefuls to brace themselves for five hours of mental torture in Sunday's final-round shootout for the Stonehaven Cup.
Scott emerged from a dramatic third round, which seemingly put paid to Rory McIlroy's quest for back-to-back championships, just one shot off the lead.
Halfway leader Greg Chalmers ground out an even-par 71 in testing conditions to remain on top, with Brett Rumford and American ace Jordan Spieth carding 69s to join the two-time champion at five under for the tournament.
Scott and veteran Rod Pampling also signed for 69s to be tied fourth at four under - but McIlroy imploded to be six shots off the pace.
The world No.1 had a triple-bogey and double-bogey in back-to-back holes mid-round to plummet from a share of the lead into a tie for 14th at one over after a Saturday-shocker 76.
Only eight players ended the round in red figures as blustery winds and baking greens turned so-called moving day into grinding day at The Australian Golf Club.
And Scott was predicting more of the same on Sunday as 23 players within six strokes of the lead battle it.
"In these conditions, it's going to take an incredible round just to make sure you're in with a chance the last few holes," he said.
"You probably saw it slipped pretty quickly for a few guys out there today and, if you're not careful, that can happen and I certainly don't want to do that.
"So it will be a thinking hat on right from the first tee."
Of the frontrunners, Scott will carry the momentum into the final round after rebounding doggedly from a horror five-over start on the front nine on Thursday.
"I wasn't feeling great going to the 10th tee and managed to claw my way back into it and hopefully I'll have a shout when it comes down the last tomorrow," said the world No.3.
Long-hitting amateur Todd Sinnott (73) is outright sixth at two under - two behind Scott and one ahead of rising star Jake Higginbottom (72) and Sydney touring professional Aron Price (69).
After only making the half cut right on the number, Queenslander Daniel Nisbet fired the round of the day in the easier morning conditions - a bogey-free four-under 67 - to surge up the leaderboard into equal ninth at even with the card.
Chalmers rebounded from a bogey-bogey start with birdies on the sixth and 14th holes to retain a share of the lead in his bid to join some of golf's all-time greats, including Jack Nicklaus and Gary Player, to win at least three Australian Open crowns.
Spieth, the world No.14 and 2014 Masters runner-up to Bubba Watson, showed his class to birdie the last to join Chalmers and Rumford on top.
Rumford mixed four birdies with two bogeys to give himself a shot at winning a maiden national championship, while 45-year-old Pampling ignited his round with a spectacular eagle two on the 401-metre par-4 10th.
Holing out from 120 metres, Pampling rode the momentum all the way through the back nine.
