The Triple Eight driver set up the win with a bold move at the first corner, running a high line to sweep past the pair of fast-starting Penske Fords.
He then went long in the first stint, not taking his mandatory service until Lap 14.
That meant being undercut by both Chaz Mostert and Scott McLaughlin, who had stopped on Laps 5 and 6 respectively, but van Gisbergen had the benefit of new rear rubber for the run home.
That helped him pass McLaughlin on his out-lap, before taking the lead off Mostert at the start of Lap 15.
From there he was able to cruise to a 1.1s win.
"What a turnaround from yesterday," said van Gisbergen. "We had no tyre life, we kept blistering them. I struggled at the start [today], taking it easy, and then the car came alive."
Andre Heimgartner ended up second thanks to a brilliant move on both Mostert and McLaughlin on Lap 15.
McLaughlin finished third, right behind Heimgartner, while Mostert struggled with tyre life in the second stint and dropped all the way to 11th by the finish.
That paved the way for Fabian Coulthard, who had run third early in the race, to charge home in fourth, making it an all-Kiwi top four – a first in Supercars history.
Jamie Whincup, meanwhile, dropped 50 points in the title battle with McLaughlin thanks to a lowly 17th place finish.
The seven-time champion was making decent progress from 11th on the grid, only to lose a heap of time during his stop due to an air spike issue.
He's now 201 points adrift of McLaughlin with five races to go.
Race 2 results:
|1||97||Shane van Gisbergen||Holden Commodore ZB|
|2||7||Andre Heimgartner||Ford Mustang GT||1.146|
|3||17||Scott McLaughlin||Ford Mustang GT||1.874|
|4||12||Fabian Coulthard||Ford Mustang GT||12.204|
|5||99||Anton De Pasquale||Holden Commodore ZB||15.864|
|6||15||Rick Kelly||Ford Mustang GT||16.030|
|7||9||David Reynolds||Holden Commodore ZB||16.885|
|8||6||Cameron Waters||Ford Mustang GT||17.187|
|9||8||Nick Percat||Holden Commodore ZB||20.086|
|10||55||Jack Le Brocq||Ford Mustang GT||25.532|
|11||25||Chaz Mostert||Holden Commodore ZB||25.570|
|12||14||Todd Hazelwood||Holden Commodore ZB||25.626|
|13||20||Scott Pye||Holden Commodore ZB||25.678|
|14||44||James Courtney||Ford Mustang GT||26.806|
|15||18||Mark Winterbottom||Holden Commodore ZB||27.537|
|16||2||Bryce Fullwood||Holden Commodore ZB||27.847|
|17||88||Jamie Whincup||Holden Commodore ZB||33.524|
|18||3||Macauley Jones||Holden Commodore ZB||33.861|
|19||22||Chris Pither||Holden Commodore ZB||39.069|
|20||19||Alex Davison||Holden Commodore ZB||39.462|
|21||4||Jack Smith||Holden Commodore ZB||39.764|
|22||35||Garry Jacobson||Holden Commodore ZB||43.558|
|23||5||Lee Holdsworth||Ford Mustang GT||43.630|
|24||34||Zane Goddard||Holden Commodore ZB||1'07.567|
|View full results|