The championship battle boiled over at Pukekohe Park Raceway in today's first race when the two Red Bull Racing teammates came together and ended with Jamie Whincup seriously damaging his title hopes and Shane van Gisbergen taking a decisive lead with three races to go.
Both Holden cars spun as a result of contact and Whincup was given a penalty, which saw him drop to last. His New Zealand teammate was able to recover to finish third and open up a 197-point championship lead.
Ford's Mark Winterbottom won the race from DJR Team Penske's Scott Pye.
The 27-year-old Kiwi made a poor start and was overtaken off the line by Winterbottom and Pye by the first corner before get got back in front the latter by the end of the opening lap. At the same time Whincup jumped a spot and then cruised past both DJR Team Penske Fords to get on van Gisbergen's bumper within the first five laps.
The two went toe-to-toe as they have done all weekend and, to a degree, all season.
It all got too much on lap 12 however when Whincup launched a dive down the inside at the hairpin and locked his rear tyres and slid into the other Red Bull Holden. Both cars spun and suffered minimal damage.
The New Zealander re-entered the track in eighth and Whincup a few spots back but was handed a drive-through penalty by race control for causing the incident, dropping him to the back of the field.
Despite complaining of damage to the rear of his car van Gisbergen managed race back through the field and finish on the podium.
Whincup finished 25th as a result.