Adam Scott has slipped from a seemingly impregnable position all the way back to a share of the lead with unheralded countryman Peter Wilson at the halfway stage of the Australian Masters at Huntingdale.
The world No.12 led by as many as five strokes midway through day two on Friday.
But a double bogey on the 10th, a bogey on the 13th and another dropped shot on the 18th completely changed the complexion of a tournament which had been shaping as a victory procession for Scott, the 2012 and 2013 Australian Masters champ.
He eventually signed for a one-under 70 to be at eight-under 134, level with the unheralded Wilson, who has shot two successive rounds of 67.
A stroke back in outright third was Masters specialist Matt Guyatt (69), who has twice finished in the top 11 in the past three years.
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Scott was only able to find one of five fairways with his wayward driver, a problem compounded by the fact the pros are forbidden from using one-woods on the practice range at Huntingdale.
"I had a lovely start, playing really solid and then a couple of loose shots on the back nine and I was just grinding to get it into the clubhouse," he said.
"That's the way it goes.
"It was a shame because I felt like I didn't do too much too bad but the driver cost me three or four shots.
"I just couldn't get it on the fairway to take advantage of the par fives.
"With a solid back nine I would have been in a really commanding position going into tomorrow. Not that I was really thinking of that but that's how it would have been."
Scott's third-round partner will be the unheralded Wilson, who vowed not to be intimidated.
"I'm looking forward to seeing how he plays," he said.
"He's up there with the (Greg) Normans and the Tigers of the world but who knows what's going to happen.
"I could shoot 64 and he could shoot 74 or vice versa.
"It's golf and you've just got to try and get it in the hole the best you can."
There are 18 players within five shots of Scott and Wilson on a crowded leaderboard.
Brett Rumford shot the day's low round of 64 to be tied for fourth with American George McNeill.
US PGA Tour stalwart John Senden was in the group tied for sixth at five-under.
Among the names to miss the halfway cut were big-hitting Belgian Nicolas Colsaerts and Australian Presidents Cup team member Steven Bowditch, the second-highest ranked player in the field.
