Holdsworth was 37.7s clear of the field on lap 88 when the balance of the field prepared to throw primary drivers behind the wheel. Behind him, Moffat and Tander jousted over the effective lead, with Tony D’Alberto 13 second behind.
Holdsworth stopped from the lead on lap 92, handing the front-running to Moffat.
The primary driver cycle began once the Davison brothers swapped hands on lap 94. Holdsworth’s march continued following his stop, passing Craig Lowndes at Griffin’s Bend on lap 96.
D’Alberto handed over to Anton De Pasquale on the following lap, and Lowndes to Whincup on lap 98. Whincup returned to the race and was forced to defend from a racy De Pasquale, with Kostecki keeping a watching brief.
Moffat handed over to Waters on lap 99, and Tander to van Gisbergen on lap 100. Van Gisbergen had 6.4s to Waters, and a further 10.4s to Nick Percat, once the champion-elect’s tyres came to temperature.
A rogue echidna at the Cutting triggered the second BP Ultimate Safety Car of the day on lap 105, ending an 86-lap green run.
Mostert took over from Holdsworth under yellow, with Waters stopping again on the following lap with the race neutralised.
The race restarted at the end of lap 108, with van Gisbergen leading, Mostert, Whincup, De Pasquale, Waters, Bryce Fullwood, Percat and Kostecki. Kostecki muscled past Percat at the Cutting as van Gisbergen tried to build a gap on Mostert.
Fullwood was Kostecki’s next victim at Murray’s Corner, and he chased the leading five cars up Mountain Straight.
Van Gisbergen baulked Mostert at Griffin’s Bend, allowing Whincup safe passage into second into the Cutting. De Pasquale raced past Mostert into Sulman Park, with Kostecki pushing past Waters in a gutsy manoeuvre across Reid Park.
Kostecki was eighth at the restart; in just two laps, he was up to fifth. Mostert, smarting after the previous lap, swiftly cleared De Pasquale at Murray’s Corner and set off after Whincup.
However, the balance of the field dived into the lane when the Safety Car was called for a third time following an accident across the top for Jayden Ojeda.
Whincup was forced to double-stack behind van Gisbergen, and Will Davison behind De Pasquale. Davison was released into the path of Whincup; the two were 11th and 12th in the queue when the race restarted. Davison was handed a five-second penalty over the incident.
A short-fuelled stop for Mostert helped the pole man into the effective lead ahead of Kostecki, with van Gisbergen, Percat, Waters, Tim Slade and De Pasquale.
David Reynolds, who didn’t stop under yellow, led the field to the lap 117 restart. Kostecki, van Gisbergen, Percat and Waters shadowed Mostert, with Waters, Slade, De Pasquale, Fullwood and Todd Hazelwood completing the top 10.
Davison and Whincup cleared Hazelwood and set off after the lead pack. Davison and Whincup were the beneficiary when Fullwood nudged De Pasquale at Murray’s Corner.
Van Gisbergen, who was reportedly managing an engine sensor issue, cleared Kostecki for third and set off after Mostert.
Mostert and van Gisbergen cleared Reynolds, with the latter overtake completed just before the Safety Car was called for a fourth time when Kostecki found the Forrest’s Elbow barrier.
De Pasquale, who had been dumped to 11th, stopped for 11 seconds of fuel and tyres under yellow, and rejoined 16th.
Mostert led van Gisbergen, Kostecki, Percat and Waters at the lap 124 restart, with Waters taking fourth from Percat on the following lap.
All the while, Mostert turned the screws on van Gisbergen, setting the fastest lap four laps in succession and eking the lead out to 2.1s. By lap 133, the margin was 2.9s. By lap 137, it was 4.5s.
Mostert and Kostecki made their final stops from first and third on lap 138, with Davison also stopping and serving his penalty.
Van Gisbergen and Waters stopped on the following lap; van Gisbergen held position, but Waters jumped Kostecki for the final spot on the podium.
The Safety Car was called for a fifth time when De Pasquale crawled to a halt exiting the Cutting. The race restarted with 19 laps remaining, but a Broc Feeney - who was ninth - accident at McPhillamy returned the field to yellow.
Mostert put 0.9s on van Gisbergen on the first green lap, with Waters 1.1s further behind. It quickly became a two-horse race, with Mostert and van Gisbergen leaving Waters behind.
Mostert pushed further into the distance; he clocked the fastest middle sector of the race on lap 151, and was 2.6s clear by lap’s end. By lap 154, it was 3.6s.
On lap 155, van Gisbergen slowed with a right-front puncture; Waters sailed past out of the Cutting into second, before Kostecki brushed the wall into McPhillamy.
Mostert ran home free to the end, crossing the line 3.7s ahead of Waters to secure career victory No. 16. For Holdsworth, it was his first win since Winton 2014.
Mostert also secured third in the championship standings.
"I tell you what, it's better than when Gizzy is breathing down your neck,” Mostert said.
"I hit that drum early in the race so I changed my driving style to stay away from all curbs and still try to extract speed.
"It's one of those things when you're leading the race with eight laps to go you start hearing all these funny noises in the car and you never think you are going to get there.
"Sorry about the in-lap but I saw Gizzy do it last year and I didn’t want him to steal our thunder.
"So good to go around the track one extra time and see all the fans, it's really cool."