COOLUM, Australia, Dec 15, 2012 (AFP) - Popovic was in superb touch around the Palmer Coolum Resort course, holding off the challenge from a host of bigger name players to tighten his grip at the top of the leaderboard.
Fellow Australian Anthony Brown was two shots off the pace after shooting an eight-under 64 to ensure an unlikely pairing heading into the final day of the OneAsia co-sanctioned $1.25million tournament.
Australian veteran Peter Senior was a further shot back in equal third alongside Matthew Griffin, keeping alive his hopes of an historic "double double" of winning the Australian Open and PGA in the same year on two occasions.
However, China's Zhang Xinjun, who was overnight leader with Popovic, had a disappointing day, finishing five behind after firing two over the card.
Zhang was on eight-under alongside former US Open champion Geoff Ogilvy and the experienced Robert Allenby.
Popovic opened his round with two birdies in the first three holes, but slipped up with bogies at five and eight.
However, he birdied the ninth to be one-under heading into the back nine, then hit three more birdies including one at the difficult 18th to stamp his authority on the tournament.
"I absolutely crunched my three-iron down the fairway and went on from there," Popovic said of his good start.
The 26-year-old from Melbourne won the tour qualifying school last December and said that win had helped him cope with the pressure of leading at the end of all three days in Coolum.
"I've been in pressure situations before, like Q school, and that is probably the biggest pressure situation you face," he said.
Brown surged up the leaderboard following his round of 64, the equal best of the day.
After opening with a birdie at the first hole he collected further birdies at the fifth, sixth, seventh and ninth to go out in 31 shots.
Four more birdies and a solitary bogey, at the par-4 356 metre 13th hole, completed his charge.
"It hasn't been the best year for me but I've been playing better the last few months although I didn't really have any expectations at the start of the day," he said.
"But whenever you shoot 64 in any tournament, let alone the Aussie PGA, you take it."
Former British Open champion Darren Clarke retained a slim chance with an even par 72 to finish five-under.
However, South Africa's Rory Sabbatini was well off the pace on two-under.
Scores after the third round of the OneAsia co-sanctioned US$1.25 million Australian PGA at the par-72 Palmer Coolum Resort course on Saturday (Australia unless stated):
203 - Daniel Popovic 64-70-69
205 - Anthony Brown 73-68-64
206 - Peter Senior 68-70-68, Matthew Griffin 69-67-70
207 - Brendan Jones 73-67-67, Rod Pampling 71-67-69, Brad Kennedy 69-68-70, Mathew Goggin 71-66-70
208 - Stephen Dartnall 68-72-68, Robert Allenby 73-67-68, Geoff Ogilvy 67-69-72, Zhang Xinjun (CHN) 67-67-74
209 - Greg Chalmers 72-69-68, Nathan Green 72-71-66, Michael Wright 70-73-66, Richard Green 71-68-70, Matthew Millar 73-66-70
210 - James Nitties 70-72-68, Josh Geary (NZL) 69-72-69, Cameron Percy 70-70-70, Kurt Barnes 74-65-71, Jason Kang (USA) 70-69-71, Stephen Leaney 69-70-71
211 - John Senden 73-69-69, Adam Crawford 70-71-70, Bronson La'Cassie 69-71-71, Peter Fowler 70-70-71, Leigh McKechnie 70-69-72, Darren Clarke (NIR) 70-69-72, Steven Bowditch 70-67-74
Selected
212 - Kim Do-Hoon (KOR) 73-71-68
213 - Rory Sabbatini (RSA) 76-68-70
216 - Cao Yi (CHN) 73-71-72
217 - Choo Tze-huang (SIN) 67-75-75, Park Ju-Hyuk (KOR) 77-67-73
218 - Park Hyo-Won (KOR) 71-73-74
221 - Choi Joon-Woo (KOR) 74-69-78, Pravee Visalkt (THA) 74-71-76
223 - Li Xinyang (CHN) 72-73-78