MELBOURNE, Nov 17, 2012 (AFP) - England's Poulter came from five shots off the overnight lead to shoot a masterful eight-under 64 to be 13-under 203 after 54 holes and just shading Scott (67).
At one stage Poulter looked certain to challenge the course record of 63 set by Australian Cruze Strange last year.
Both he and Scott refused to concede ground as the battle to don the tournament's gold winner's jacket appeared to be just between them over Sunday's final 18 holes.
"We have a few shots on the field but we can't go at it as if it's match play," Poulter said.
"It might be a little different if we are still in front coming down the stretch but anyone back in the field is capable of shooting a low number on this golf course."
Home favourite Scott agreed. "I'm not going to start worrying about Ian (Poulter). You only worry about that coming down the stretch. There's a low score (for anyone) out there if you play well."
Australian halfway leader Matthew Guyatt (75) was six shots off the lead in third spot.
Poulter and Scott put on a master class playing alongside each other in Saturday's third round and fired 17 birdies between them.
Poulter, who won the WGC-HSBC Champions in China earlier this month, bounced out of the blocks and was six under for the day after 10 holes.
Scott said this left him with no choice but to knuckle down and keep in touch.
"He (Poulter) was going to run away with it the way he started. Sometimes when that happens you can see the shots (the other player is making) and follow his lead," Scott said.
Quizzed about his chances of winning his first event for the year, Scott said: "We're all going up against one of the toughest competitors in the game and he's leading."
Scott lamented two soft bogeys on holes 16 and 17 and alluding to his collapse in this year's British Open at Royal Lytham added with a wry grin: "I've done that before. I need to eliminate any mistakes tomorrow."
Scott said he had to make a five-metre birdie putt at the final hole to match Poulter's brilliant 9-iron approach which finished less than a metre from the hole from 146 metres.
"I really needed to make it. He's high on confidence and a tough competitor. It was important I did not let him get two ahead," he said.
Poulter said playing alongside Scott had helped his game.
"Collectively we had 17 birdies. Adam played some great golf as well. It's nice to play with someone you know really well," he said.
"You feed off them, they feed off you, and I think that's what we did today."
Northern Ireland's Graeme McDowell moved to joint 13th at one-under after Saturday's round of seven birdies in a five-under 67.
New Zealand's Mark Brown climbed to fourth position at six-under after a 67, while fellow Kiwi Gareth Paddison shared fifth position with Australians Chris Campbell and Craig Hancock at five-under.
Third round scores at the Australian Masters at Kingston Heath (par 72) in Melbourne on Saturday (Australia unless stated):
203 - Ian Poulter (ENG) 67-72-64
204 - Adam Scott 67-70-67
209 - Matthew Guyatt 65-69-75
210 - Mark Brown (NZL) 72-71-67
211 - Gareth Paddison (NZL) 71-71-69, Christopher Campbell 70-72-69, Craig Hancock 68-71-72
213 - Jake Higginbottom 68-75-70
214 - Jason Norris 71-74-69, Jason Scrivener 71-73-70, Paul Gow 68-73-73, David Bransdon 71-69-74
215 - Graeme McDowell (NIR) 71-77-67, Peter O'Malley 68-78-69, Brody Ninyette 69-76-70, Cameron Smith 70-73-72, Richard Green 71-72-72, Chris Gaunt 72-70-73, Michael Hendry (NZL) 67-69-79
Selected scores
217 - Stuart Appleby 71-73-73
218 - Robert Allenby 72-76-70
220 - Thomas Petersson (SWE) 72-76-72