Problems for Richard Gartner on the opening lap saw the Safe-T-Stop Lamborghini drop down the order, before the Queensland Raceway round winner was forced out of the race after a mix up in the pits.
Taking out the Challenge Modern Class was Mark Griffith, who scored maximum points for the weekend in the Griffith Corporation Ferrari F430.
He found himself locked in battle with Justin McMillan in the second half of the race, the Interlloy M Motorsport KTM X-Bow GT4 enjoying the slippery conditions to mix it with Griffith.
Scott Hookey picked up second in Challenge Modern in the Fiorano Motorsport entry with John Nikolovski and Jamie Arratoon rounding out the podium in the Aranik Ferrari 458 Challenge.
With victory in Race 1 and second in Race 2, Salmon took out the round to close the title battle to just 49-points heading to the final round of the 2017 season at Wakefield Park (November 18 - 19).
With a maximum of 220 points on offer at the season finale, the title chase is now a straight fight between McLaughlan and Salmon after Gartner's weekend saw him drop 225-points behind the series leader.
Before then, Australian GT heads to Sandown next weekend for the final round of the CAMS Australian GT Championship (September 15 - 16), while the CAMS Australian Endurance Championship will head to New Zealand for its final two rounds starting with the Laser Plumbing & Electrical Hampton Downs 500 on October 27 - 29.