SYDNEY, November 30, 2013 (AFP) - Scott holed a short birdie putt at the last hole in a round of 68 to move to 16 under par in bright but testing conditions on the Royal Sydney course Saturday.
Double major winning Rory McIlroy let slip the opportunity to match Scott's last hole birdie in a struggling round of 70 for a 12-under par total.
"My short game is good at the moment and I have kind of got my eye in with the putter this week," said Scott.
"But then tomorrow I would rather come out and be hitting it down the middle and take some of that pressure off myself."
Scott won the first leg of the "Triple Crown", the Australian PGA Championship earlier this month, and then successfully defended the second leg, the Australian Masters winning by two strokes last weekend.
If successful in capturing the third leg it will be his second Australian Open triumph in four years and match the effort of fellow Australian Robert Allenby who first won the "Triple Crown" in 2005.
In addition, if Scott does succeed he also will match Tiger Woods as the only player this season to savour five victories.
"It will be huge for me to win not only a second Australian Open but the Triple Crown," said Scott.
"I am excited at the moment as I have a great opportunity but in 18 holes we have already seen a lot of shots swing around.
"I teed off in these situations before and won tournaments and I have teed off in these situations and lost tournaments, so all I can do is play as hard as I can.
"I think the guy who wants it the most will end up winning."
The World No. 2 ranked Scott went into day three leading McIlroy by just two shots but then soon found himself five shots clear of the Northern Irishman when McIlroy bogeyed the fourth and dropped two shots at the fifth.
McIlroy was easily outdriving Scott but he failed to get the better of his US Masters-winning rival with plenty of indifferent second and third shot play.
Scott continued to stamp his authority with three birdies in succession from the seventh and while the Australian dropped a shot at the 11th he then birdied 14 before finishing with four straight pars.
"It was a tricky day with the wind and trying to keep up with Adam was tough," said McIlroy.
"Adam is playing... so solid and it's just that I left a few out there and that means I am four back going into the last day.
"So I am going to have to get off to a fast start and try and catch him."
Scott and McIlroy will again play the final round together, with McIlroy seeking to win for a first time this year.
The Australian trio Matthew Jones (72), Richard Green (73) and Max McCardle (69) are in third place on eight under par.
Australia's World Cup winning hero Jason Day birdied five of his six closing holes in an equal best round of six-under-par 66 to move a share of 10th place at six under par.
Leading scores after the third round of the Australian Open at Royal Sydney Golf Club (par 72) on Saturday.
200 - Adam Scott (AUS) 62-70-68
204 - Rory McIlroy (NIR) 69-65-70
208 - Matthew Jones (AUS) 68-68-72, Richard Green (AUS) 69-66-73, Max McCardle (AUS) 68-71-69
209 - Stuart Appleby (AUS) 75-67-67, Nathan Holman (AUS) 69-72-68, Scott Arnold (AUS) 70-70-69
210 - Jason Day (AUS) 70-74-66, Ashley Hall (AUS) 71-71-68, Rhein Gibson (AUS)71-70-69, Bryden Macpherson (AUS) 71-70-69
211 - John Senden (AUS) 73-68-70, Adam Bland (AUS) 69-72-70, Anthony Murdaca (AUS) 71-74-66, Brady Watt (AUS) 68-70-73
212 - Alistair Presnell (AUS) 67-71-74, Tom Bond (AUS) 69-73-70, David McKenzie (AUS) 66-75-71, Nick O'Hern (AUS) 70-72-70, Rod Pampling (AUS) 75-68-69, Ryan Ruffels (AUS) 77-67-68