Whincup leads on 1847 points from Craig Lowndes (1800) and Will Davison (1792).
The result also ensured that Holden can no longer be beaten in the V8 Supercars Manufacturers Championship.
Townsville Street Circuit
Lowndes is the right man: Skaife
Rain played a factor in the first qualifying for the Sydney 500.The track dried at the end but several top drivers will not have a shot at the pole; including Whincup!
Practice day for the Australia V8 Supercars was extremely hot; especially for the drivers on and off the track Homebush circuit.
John Maricic, V8 Supercars correspondent
Now the sport makes its debut in the US at the Circuit of the Americas next week where every team will be running at the track for the first time.
V8 Supercars Australia Championship