Canberra golfer Chris Campbell.

Canberra golfer Chris Campbell.

CHRIS CAMPBELL rates himself a 100-1 long shot to storm past world No.6 Adam Scott and England's Ian Poulter and claim the Australian Masters title on Sunday.

But the Canberra golfer was confident he could put in a good final round on the tough Kingston Heath course and capitalise on sitting equal fifth.

Campbell shot three-under par on Saturday to take himself to five-under and eight shots behind leader Poulter. Scott is one shot behind the Englishman.

Suffering from a back injury, Canberra's Matt Millar shot four-over to be even through 54 holes and in equal 20th place.

Campbell thought Scott was unlikely to repeat his final-round meltdown at the British Open earlier this year, where the Aussie gave up a four-shot lead in the final four holes.

He thought either Scott or Poulter, or both, would break par, which meant he'd have to shoot ''nine or 10-under to be a chance''.

''I'm confident if the stars align perfectly then it could happen, but if I was confident of that I'd be insane because it's a 100-1 shot,'' Campbell said.

His round started disastrously with two bogeys in the opening four holes. Then he hit a hot streak, led by his putter, and produced five birdies over the rest of the round to keep himself on the leader board.

''You've got to have putts [to make] birdies, but it takes a bit more than just putting,'' Campbell said. ''I definitely holed a couple of good par putts and then dropped a few birdie putts to get myself thinking positively.''

It could be a big day for the Campbell family. His sister Nikki is playing in the Daio Paper Elleair Ladies Open and Campbell said she needed a top-five finish to avoid the Japan Tour qualifying school.

She was equal third on five-under with the final round on Sunday.

Millar, who suffered a back injury during the opening round, also has an important date with the Japan Tour qualifying school.

But his first concern will be getting through the final round in Melbourne.

He had a horror start to the penultimate round, bogeying four of the first seven holes before he scored a double-bogey on the eighth. He managed to steady and claw back a couple of shots, including chipping in on the 18th.

Millar's back had improved a lot from Friday, he said, but it took him until the ninth hole to find his rhythm.

His chip shot was a case of practice makes perfect.

''I practised there on Tuesday for probably a good 20 minutes out of that little bowl and it's interesting that I'd get one out of there and hole it,'' Millar said.

''It was a great shot actually, it just fell in the front door beautifully. It was a good way to finish.''