Chalmers, who started the day at  four shots behind the leader, stormed into the lead at five under after the second round following an impressive afternoon at the Australian Golf Club –  one shot ahead of Rory McIlroy, Adam Crawford, amateur Todd Sinnott and American Conrad Shindler.

The afternoon belonged to Chalmers, who rode his luck at the 11th when he relied on a ricochet off a member of the gallery to eventually birdie.

"I think it was a spectacular result, I don't know if it was a spectacular shot," Chalmers said.

Earlier it was Scott storming back into contention and moving into the top 10 with a round of five under, finishing just three shots off the pace heading into the weekend.

In the space of 13 holes, the former world No.1 had ripped up a seven-shot deficit to overnight leader and playing partner Jordan Spieth to bits. Spieth, this year's US Masters runner-up, waxed lyrical late Thursday about Scott's ability to smile through gritted teeth when the worst nightmare of Australian Open officials was unfolding. It was a case of not who out of Adam and Rory would take the cut of the $1.25million purse, but whether Adam would make the cut at all.

Instead, Scott marched straight to the range and worked more on ironing a few kinks in the mind rather than anything in blighting that effortless swing.

Sinnott, who played his practice round with McIlroy on Tuesday, fired four under to finish the day one shot off the pace, while Spieth dropped a shot to remain two shots behind Chalmers.

On Friday, Spieth scored a meandering one-over 72, thankful for a birdie-birdie finish which at least had the 21-year-old masking any further damage on the Scott-anointed moving day.

And that's exactly what it was. An eagle on the 14th – Scott's fifth hole for the morning – got the ball rolling and he clung on for dear life on the inwards nine thanks to some exquisite chips and nerveless putting to sign for a bogey-free five-under 66.

On the early eagle, Scott said: "It's an incredibly different feeling of being two-under to two-over, how you feel about the state of your game. So I tried to keep that rolling [on Friday] and I needed to because it was the only chance I had to kind of be in touch with the lead. I was scrambling but I scrambled well and then, all of a sudden a couple of good shots down 14, I make an eagle and momentum's on your side."

Much like it was on McIlroy's side last year, when the Northern Irishman lifted himself off the Australian Open canvas early in the tournament to chalk up a Stonehaven Cup heist when Scott was almost over the horizon.

"I didn't really think about that [on Friday] but I guess when you've played a lot of golf tournaments you know there's a long way to go over 72 holes and I played such a great round last year, that gap can close over the next 54 and that's exactly what happened," Scott said.

McIlroy had only one par on the final 10 holes, finishing his round with an eagle, birdie, bogey, birdie, birdie.

"Look at the leaderboard and it is very hard and unless someone can separate themselves [it will stay that way]," he said. "But I'll be going out there [on Saturday] to shoot a low score to see where it puts me for Sunday. I still expect a few guys to have a chance on Sunday."