A 20 foot putt at the final hole completed a run of three birdies in his last five holes for Popovic and a round of 69 to open up a two shot lead over Brown and three over Peter Senior and yet another Victorian in Matthew Griffin.
Brendan Jones, Rod Pampling, Brad Kennedy and Mathew Goggin are one further back while another four players are another shot adrift.
Once again, championship Sunday at Coolum promises a drama filled day, the tournament having become renowned for final round shootouts. Given there are 17 players within six shots of the lead then there appears little doubt, in what appears to be the 11th and final staging of the event, that pattern will continue.
"I'm over the moon," said the leader. "I couldn't be happier. I knew that I had it in me and I still know that I have one more good round tomorrow in me, I've just got to keep my routine going, in moments like these and I've said it before that you just have to keep in routine. What I have been doing has been working this week and tonight is going to be exactly the same and so is tomorrow morning in my warm up.
"I felt brilliant (today), obviously again first tee and a big crowd around obviously because Geoff Ogilvy and the last group of the day, first tee I was a bit nervous but I absolutely crunched my three iron down the fairway and just went on from there."
"I've been in pressure situations before," added Popovic when asked about the pressure he is likely to experience in tomorrow's final round. "Like say Q School which is for me almost the most pressure that you have for the year because it determines where and how many tournaments you are going to play for the rest of the year.
"It does surprise me in a way that I did handle it so well today without sort of having my A game, but I am going to walk away from here thinking this can be done tomorrow and I'm going to give it a fair crack.
Popovic put a lot of his impressive showing this week down the inclusion of a new putter in the bag and it was clear that he and his new found friend have developed something of a love affair.
"This thing right here (lifting his putter) has saved me at least three or four strokes around at least and it is never going to leave my side."
Anthony Brown is currently 1055th in the world and has seldom contended in an event of this sort. He has played a little better in recent weeks however. "Yeah look it hasn't been the best year this year for me," he said. "I have been playing a lot better the last couple of months so I knew there was a good one in me. I guess I didn't really have any expectations at the start of the day but whenever you shoot 64 in any tournament let alone the Aussie PGA you'll take it, so very happy.
Tomorrow is a huge day for the Victorian not only given the money at stake but the chance to consolidate his status in Australian golf and to confirm that the work he has been doing is paying off.
Brown has finished third in Tier 2 events in Australasia but probably the biggest cheque he has earned to date was when 3rd to Mike Hendry at the Indonesian Open two years ago.
Peter Senior birdied three of his last six holes to move within two of the lead before Popovic 's last birdie but given that he is just three shots behind he is looming as a threat to win again at Coolum. If he does it would be for the third time in the event's tenure at the former Hyatt Regency Coolum (now Palmer Coolum Resort) and the fourth time in the event overall.
"I'm pretty happy with the way things are going," said Senior, providing further reason for concern amongst those ahead of him. "I played a lot better today than I had even last week, I hit a lot better quality shots, driving it really well and I just hitting it and picking up my tee which is always a great feeling, sort of sets the holes up a little bit.
"I hit some better iron shots today that felt better than what I have been doing. Made some birdies on some good holes, like 14 and 18 today, those were the real bonus holes. I just haven't making birdies on the par 5's, 15 par 5's so far this week and I think I'm about 3 under, the longer hitters are sort of knocking them to pieces so par 5's are really letting me down.
"Most of them (the par fives) are out of my reach and it's two really good shots, brings in a lot of trouble like the tee shot on the first, I can't carry the corner bit so I either hit it in the bunker or I hit it in the water so, why do that, at least hit two shots down there and I have a wedge in and opportunity to make birdie."
Senior plays well here because the layout, where length is not necessarily and advantage, suits his game and because he loves the environment and the atmosphere of the Resort.
"I've had my family up this week so it has been good to go up to the Market Place and just sit down and have a quiet dinner. We've just about exhausted every restaurant up there, but when you stay on a complex like this you don't really want to go off site, so it's always a good thing just to go and have a shower and walk a couple of hundred metres up to sit down and have dinner, it's a great feeling. I'll do the same as what I've been doing the rest of the week, but I'm really enjoying having friends and family around."
So what does Senior think about the congested nature of the leaderboard? "It's great, that's the way tournaments should be, it's great for the winner to win by half a dozen and have no problem but I think it is great for everybody when there are eight or nine guys in the mix. The back nine here can show its teeth pretty quickly with the amount of water around the place, one missed shot here and there and it can turn right around and that's the beauty of this place."
Brendan Jones has put himself into position to again contend on Sunday as he did last week at the Australian Open. Jones is a 12 time winner on the Japan Golf Tour and once on the Nationwide Tour and while he has not played events in this country often he is a proven winner. That might well be too his advantage in what will be a battle to the finish tomorrow.
Like Jones, Brad Kennedy also won on the Japan Golf Tour in 2012 while Rod Pampling plays this gof course well as does Mathew Goggin.
Tomorrow appears as if it will be the swansong for the Australian PGA Championship at the Palmer Coolum Resort but the stacked nature of the leaderboard promises to send the event out in the best possible style.