Tour veteran Peter Senior celebrated a richly deserved two-stroke win at Huntingdale Golf Club on Sunday but the trophy was virtually gift-wrapped for former world number one Scott halfway through his second round.
The 2012 and 2013 champion had marched to a five-stroke lead after a bogey-free run of 27 holes, but from there it became a grind.
With his driver, irons and putter all misbehaving, Scott fell back into a share of the lead after the second round and crashed during the third with a six-over 77.
Five strokes off the pace on Sunday, Scott dug deep to claw within three of the lead but a double-bogey on the par-five seventh took the wind out of his sails and his challenge ended with another dropped shot on the 15th.
He finished fifth after a final round 69 and felt the week was a microcosm of a frustrating, winless year.
“I think I played okay. It’s kind of hard to know after yesterday’s (round) left my head spinning a little bit because I just played so poorly,” the 2013 U.S. Masters champion told reporters.
“(That was) some of the worst golf I’ve played this year and really disappointing.
“So, it was a big ask to be able to go low today.”
As Senior marched to his third Masters title, draining a number of long birdies with a broomstick putter, Scott laboured for the most part on the greens with the short putter.
Last month, Scott gave up the broomstick which he won with at Augusta in readiness for the ban on anchoring in 2016.
The transition has had its setbacks and barring some fine putting in his opening round 64, Scott struggled to find the hole from outside 10 feet.
Scott, nonetheless, said his week had left him with a “competitive mind‑set” for the Open at the Australian Golf Club in Sydney.
“Three pretty good rounds this week, that’s how you have to look at it, and one you’d like to forget about,” he added.
“Hopefully that means I’m not far away from four good rounds … I’m going to have to tighten it up just that little bit and hit some better shots overall.”
(Editing by Julian Linden)