Fabian Coulthard halted Jamie Whincup's winning streak by defeating the Triple 8 Holdens in race three of V8 Supercars' Austin weekend.
Whincup had won both Saturday races to add to his two wins out of three in the preceding event at Barbagallo.
But though he took another double pole in Sunday's qualifying sessions and led the early laps of race three, Whincup was elbowed down to third as Mark Winterbottom and Coulthard put firm moves on him.
His team-mate Craig Lowndes then further demoted Whincup to fourth.
Winterbottom narrowly fended off Coulthard until the pitstops, when a cross-threaded wheelnut dropped the frustrated Ford driver to seventh.
A safety car period for debris brought the pack back onto Coulthard's tail immediately after the pitstops, with Lowndes and Whincup right behind him for the restart.
But Coulthard had enough in hand to keep Lowndes at bay, while Whincup drifted away in third.
There is still a question mark over Coulthard's success, though, as race control is investigating whether he maintained proper speed approaching the restart.
Rick Kelly's Nissan had left the pits in fourth in the new car's best run yet.
A slow restart then left Kelly vulnerable to attack, and he was elbowed back to ninth over the following laps.
Tekno duo Jonathon Webb and Shane van Gisbergen battled through to fourth and fifth, ahead of Garth Tander, Winterbottom and Coulthard's team-mate Jason Bright.
Results - 27 laps:
Pos Driver Team/Car Time/Gap
1. Fabian Coulthard Brad Jones Holden 45m24.8159s
2. Craig Lowndes Triple 8 Holden + 0.9402s
3. Jamie Whincup Triple 8 Holden + 2.5474s
4. Jonathon Webb Tekno Holden + 5.1604s
5. Shane van Gisbergen Tekno Holden + 10.4711s
6. Garth Tander HRT Holden + 10.8037s
7. Mark Winterbottom FPR Ford + 11.7817s
8. Jason Bright Brad Jones Holden + 11.9711s
9. Rick Kelly Nissan + 13.7901s
10. James Courtney HRT Holden + 15.1668s
11. Scott McLaughlin GRM Holden + 17.0564s
12. Will Davison FPR Ford + 17.0976s
13. Chaz Mostert Dick Johnson Ford + 22.5896s
14. Todd Kelly Nissan + 22.9029s
15. Michael Caruso Nissan + 23.5216s
16. David Reynolds Rod Nash/FPR Ford + 23.9679s
17. James Moffat Nissan + 24.1729s
18. Alex Davison Schwerkolt/FPR Ford + 25.7548s
19. David Wall Britek/BJR Holden + 26.0261s
20. Tim Slade Rosenberg/Erebus Mercedes + 27.3574s
21. Lee Holdsworth Erebus Mercedes + 27.9187s
22. Russell Ingall Walkinshaw/HRT Holden + 30.8187s
23. Dean Fiore Dumbrell Holden + 34.1977s
24. Maro Engel Erebus Mercedes + 34.7085s
25. Scott Pye Dumbrell Holden + 34.9064s
26. Tony D'Alberto D'Alberto Holden + 35.2637s
27. Tim Blanchard Dick Johnson Ford + 44.3659s
28. Alexandre Premat GRM Holden + 1m11.7316s