“It’s been difficult with this car, she was falling apart a bit at the end but we made it. It’s good.”
Stanaway said it was a childhood dream of his to win the race.
“It’s been incredible to be a part of this team. Teaming up with Shane, I knew we had a good shot, but you never know in this race.”
The last, and only other Kiwi pairing to win the race was Greg Murphy and Steven Richards in 1999.
Van Gisbergen, who will be leaving Supercars at the end of the season for an opportunity to drive in Nascar in the United States, guided their team over the finish line well ahead of second-placed Kostecki and David Russell. Anton De Pasquale and Tony D’Alberto were the first Ford entry home, finishing in third place.
“I’ll be back one day probably but, for now, and this is the perfect way to say goodbye,” van Gisbergen said.
Throughout the week, van Gisbergen and Stanaway had struggled to match some of the other entries in pace, qualifying to start in sixth place on the grid.
But the pair were strong over Mount Panorama on Sunday, finding the front early on, before building to a lead of over five seconds with 60 laps to go and navigating their way through the back end of the 161-lap race nicely.
With about 30 laps to go, it looked set up for a three-car shootout with van Gisbergen needing to fend off Red Bull Ampol Racing teammate Broc Feeney - who drove paired with Jamie Whincup - and Kostecki. However, a gearbox issue on lap 137 saw Feeney forced into the pits, ending his race there.
Commentators also noted Kostecki seemed to be having trouble with his steering down the stretch as well, and van Gisbergen drove the No 97 entry to a memorable win.