Haydn Barron's big day turned into a fairly wretched one - topped by a triple-bogey eight at one hole - as the Australian's two-stroke overnight lead evaporated into a three-shot deficit at the Qatar Masters.
And on a pretty calamitous 'moving day' for the Aussie challenge at the lucrative European Tour event at Doha Golf Club, his other pacesetting compatriot Harrison Endycott fared even worse in Saturday's third round.
The old friends had looked forward to their reunion in the final grouping, as Sydneysider Endycott sat in joint-second place, just two shots behind Barron, the world No.806 who must have pinched himself at being on pole for the $US425,000 ($A650,000) first prize - easily the biggest bounty of his career.
It all started ideally for the 28-year-old Barron, as he birdied the long first hole - but things started to go wrong quickly thereafter.
He dropped shots at three of the next five holes while his rivals all successfully went birdie hunting and at the long ninth, he drove so wildly that he had to take a penalty off the tee, before hacking into further trouble and eventually suffering an ignominious triple.
It meant he went out in a five-over 41 and, in the circumstances, Barron showed some real character to immediately bounce back with an eagle at the par-five 10th, followed by birdies at the 13th and 16th.
But another dropped shot at the penultimate hole meant he finished on a two-over 74, having dropped into a three-way tie for ninth, three behind the leading trio of Denmark's Rasmus Hojgaard , Frenchman Ugo Coussaud and Japan's Rikuya Hoshino, all on 10 under.
Endycott's hopes went up in smoke as he also took 41 over the first nine with five bogeys, and after a slight recovery with a couple of birdies, served up a double-bogey when he found water at the 15th.
His four-over 76 relegated him from joint-second overnight into a tie for 42nd.
Hojgaard thrived as the Aussies crumbled, shooting a five-under-par 67 as the leading trio held a one-shot lead over Scotland's Ewen Ferguson, who had the day's low round of 66, Northern Ireland's Tom McKibbin and Dane Niklas Norgaard.
Jason Scrivener, the other Australian to make the cut, was on one under, tied for 60th, after a 71.