James Courtney has withstood enormous pressure to deny Jamie Whincup a Clipsal 500 clean sweep.

The pair have shared the opening races of the V8 Supercars season.

Whincup breezed to victory in race one around the Adelaide street circuit and was hunting a hurt Courtney in the final stages of the second 125 kilometre race.

But a steely performance allowed the reigning Clipsal champ to hold steady, reversing the finishing order from race one.

On a day where the temperature soared past 38 degrees, the racing was hotter still.

A three-car battle emerged between polesitter Chaz Mostert, Courtney and Whincup.

The Ford man battled admirably despite a gulf in speed, giving way on lap 21, when Courtney picked his moment and leap-frogged Mostert, allowing Whincup to slip through as well.

The race became a two-way shootout and the six-time champ turned the screws.

With five laps to go, Courtney took damage after cutting the barrier at turn one too fine, providing a most dramatic ending to the 125 kilometre race.

A last-lap wobble around the fastest turn at the circuit sent Courtney sideways but he held on in tremendous style, celebrating with his ‘Frank the Tank’ dance on top of the car.

Mostert rounded out the race two podium.

Earlier, Whincup scored a season-opening victory after leaping from the grid to overtake surprise pole-winner Scott Pye.

Courtney shadowed him home but never mounted a serious challenge to his lead, with Shane Van Gisbergen claiming third on his debut for Red Bull Racing.

Pye, who stunned the field to win his first pole position in front of his home crowd, managed just 12th after a pit-lane bungle cost him several places.

Reigning series champion Mark Winterbottom was unable to make an impact, finishing eighth and 11th.