Jamie Whincup has moved closer to securing the V8 Supercar Championship title for a second straight season after extending his lead in the penultimate round of the year in Perth.

Whincup stormed to victory in the opening race of the weekend at Barbagello Raceway and then benefitted from strategy and an opportunistic Safety Car to finish fourth in race two.

With closest rival Will Davison forced to retire from the second race after a freak accident entering pitlane, leaving Whincup with a lead of 281 points heading to the final round of the year.

It means 28th place in the opening race in Sydney will be enough to give Whincup the title but he vowed to keep pushing to help Team Vodafone secure both championship titles.

"While I only need to finish better than 28th in one race in Sydney, there is the teams' championship which is also undecided and Craig [Lowndes] and I are desperate to achieve the double header," Whincup said. "It was no secret I was racing car #22 [Davison] today but once he was out, I pushed on as hard as I could. With the tyres I had to work with fourth place certainly exceeded my expectations today."

Team-mate Lowndes took victory in the second race of the weekend which marked the 50th race win for Team Vodafone - a performance he said was 'not bad for an old bloke'.