Holden’s Jamie Whincup has extended his championship lead over Ford rival Will Davison, winning the landmark first two V8 Supercars races held in the United States.

Whincup led home Red Bull Racing teammate Craig Lowndes in both 100km races held on Sunday (AEST) at the Circuit of the Americas.

Holden driver Fabian Coulthard was third in both races, held in front of a good-sized crowd in stifling Texas heat.

Whincup has boosted his lead to 113 points over Davison after Ford had a tough day on the sport’s American debut.

Davison was fourth and ninth in the two races.

To compound Ford’s difficult day at the office as Holden swept both podiums, fledgling manufacturer Nissan also had something to celebrate.

Rick Kelly’s Altima finished sixth in race one – Nissan’s highest V8 finish since its return to touring car racing this season.

In the opening race, Whincup powered away from second on the grid to pass polesitter Coulthard by the end of the tricky opening turn of the 27-lap event.

Then he held off teammate Lowndes in an engrossing battle for the remainder of the race following pit stops.

Once compulsory pit stops were completed – Holden driver Jason Bright among three drivers who didn’t complete their stops until the second-last lap of the race – Whincup assumed the race lead and went on to win.

The second race was far more processional, with Whincup starting on pole, holding off Lowndes from the start and driving a flawless race for victory.