The 36-year-old Briton, riding high after his Ryder Cup heroics in September, went toe-to-toe with playing partner Scott in a 17-birdie rout of Melbourne's Kingston Heath Golf Club to set up a mouthwatering finish on Sunday.
Trailing overnight leader Matthew Guyatt by five strokes, Poulter carded a sparkling eight-under 64 for a 13-under 203 total, signing off with a tap-in birdie on the 18th after landing a 163-yard nine-iron within a foot of the pin.
World number five Scott faltered with bogeys on the 16th and 17th to gift Poulter the lead but rolled in a 20-foot putt on the last for birdie to keep up the pressure and spark thunderous cheers from an enthralled gallery.
"Collectively we've had 17 birdies which is a lot of birdies on that golf course, when at times, there was a nice breeze," Poulter told reporters.
"It's nice to play with someone who you know really, really well. You can feed off them, as much as they feed off you.
"I think that's exactly what we did today. There was a great vibe on the course. There were good shots being played, nice putts being holed and it's always nice to be in a good two-ball like that."
Daylight separates Poulter and Scott from the rest of the field with Guyatt slipping down the leaderboard to be six strokes off the lead in third place after slumping to a three-over 75.
Poulter will bid to join Australian former world number one Greg Norman as only the second player to successfully defend the Masters in its 33-year history.
A formidable match-play opponent, the world number 16 compiled a 4-0 record against United States to spark Europe's Ryder Cup victory in Chicago and has been in top form since, clinching his second World Golf Championship title at Shenzhen earlier this month.
The prospect of another shootout on Sunday should entice the Englishman, who won last year's tournament at nearby Victoria Golf Club after reeling in playing partner and local favourite Geoff Ogilvy.
Trailing by two strokes in blustery conditions, Poulter won that tournament by three, and was pleased with Sunday's forecast for mild weather and strong breezes at Kingston Heath.
"It's all about not making mistakes and taking your chances... It would be an honour to (defend). I'm in a good position right now and I'm very much looking forward to trying to do that. It would be great."
On even-par after five holes as Poulter charged up the leaderboard with three birdies, Scott said he had to lift himself for fear the Englishman would leave him for dead.
"I realised at some point in there that I need to get in that same kind of rhythm or he's going to run away from me today," said Scott, who is chasing his first tournament win for the year after a number of frustrating near-misses.
"Sometimes when you're playing well, you can get in the rhythm of the other guy and you're seeing good shots and just kind of follow his lead, so I did that a little bit today and we both played nicely.
"Ian made just a couple less mistakes and hit a couple more good shots early on, so fantastic round from him today."
1 Ian Poulter -13
2 Adam Scott -12
3 Matthew Guyatt -7
4 Mark Brown -6
T5 Craig Hancock -5
T5 Christopher Campbell -5
T5 Gareth Paddison -5
8 Jake Higginbottom (AM) -3
T9 Jason Norris -2
T9 David Bransdon -2
T9 Jason Scrivener -2
T9 Paul Gow -2
- Sports & Recreation
- Kingston Heath Golf Club