Nine years after first dabbling in touring cars Coulthard toasted his maiden win, with Holden teammate Jason Bright sealing a dream one-two finish for Brad Jones Racing.
Ford's Will Davison was third.
It may have been a support category for the Australian Grand Prix but Coulthard's duel with fellow Kiwi Shane van Gisbergen demanded centre stage with the Albert Park faithful in the 12-lap blitz.
Luck had looked to be finally turning around for the 30-year-old driver after he grabbed his first career pole for Friday's opening frantic run around the Albert Park street circuit.
Coulthard had been a top-five performer in the recent opening round in Adelaide, only for mechanical problems and an oil spill to dash his hopes in the two 250km races.
But Coulthard was again ruing his fortunes after he slipped from first to fourth, behind last race winner in Adelaide van Gisbergen, when everyone completed their compulsory pit stop following a lap two safety car.
However, Coulthard made his own luck as he showed pure speed to pick away his rivals and remain firmly in van Gisbergen's rearview mirror.
And on the second last lap the stars aligned for Coulthard.
Van Gisbergen began battling mechanical problems and Coulthard swooped as his stricken compatriot drifted back into the field.
In the end van Gisbergen was one of three drivers who failed to finish.
In contrast, Coulthard was toasting his success after finishing almost two seconds ahead of teammate Bright who also had to overcome the odds on the way to the podium.
Bright qualified second on the grid but was relegated to fourth due to a practice penalty.
However, the former Bathurst 1000 winner also showed exceptional speed in a reminder to traditional powerhouse the Triple Eight Red Bull team that they won't have it all their own way in 2013.
Four-time series winner Jamie Whincup was fourth with Red Bull teammate and series leader Craig Lowndes fifth.
In another concern for Red Bull boss Roland Dane, his prized pair raised eyebrows when they came into contact late in the race.
Whincup survived to finish the race but Lowndes slipped from third to fifth due to tyre degradation.
There was plenty of action from the opening lap when Nissan's Michael Caruso and Holden driver Tony D'Alberto came into contact.
But the safety car only emerged on lap two when Holden's Alexandre Premat inexplicably shunted Lee Holdsworth's Mercedes.
Friday's second race starts at 1420 AEDT.