Coulthard wins amid Kiwi Supercars bust-up

Tensions at the top of the Supercars field have boiled over at Sydney Motorsport Park, with Scott McLaughlin spinning out Shane Van Gisbergen in a fight with major title ramifications.

Fabian Coulthard took honours ahead of Chaz Mostert and Jamie Whincup in a spiteful 120km race on Saturday.

The win came after two Kiwis - series leader McLaughlin and reigning champ Van Gisbergen - duelled to fatal effect for the race lead.

The Red Bull Holden pulled off an ambitious heist for the lead at a restart, bumping and grinding past the DJR Team Penske man.

McLaughlin responded with a crude bump that spun Van Gisbergen around, earning himself a 15-second penalty and ruining his own race.

Coulthard was the key beneficiary, bolstering his own championship hopes.

McLaughlin retains the series lead but his margin to both Whincup and Coulthard has taken a hit - along with his own pride.

After the race, he went straight to Van Gisbergen to apologise - with his rival accepting his handshake.

"What can I say, it was an absolute ballsup on my behalf," McLaughlin said.

"Sorry to him and his team. It's not the way I want to do it ... it's not my style."

Mark Winterbottom missed out on a first win of the season despite surging past polesitter McLaughlin off the line.

Master starter Van Gisbergen also overtook McLaughlin from the second row.

Van Gisbergen showed terrific pace all race, hunting and passing Winterbottom for the race lead on lap 11.

A wide run on turn two - the same corner where he claimed Winterbottom - allowed McLaughlin to reclaim the lead by undercutting Van Gisbergen with a shorter pit stop.

But Todd Kelly's tyre explosion set the stage for the dramatic clash - which is likely to fuel tension along pit lane for many races to come.

Earlier on Saturday, McLaughlin claimed his 12th pole position for the season, locking down the season's pole award with nine races remaining.

He could match Jamie Whincup's all-time qualifying record of 13 as soon as Sunday in Sydney.