He is the fifth new winner of 2007, but the sudden competitiveness of his Alfa Romeo probably owed more to the fact that he wasn’t carrying any success ballast.
Championship leader Augusto Farfus failed to score meaning the title battle remains very open.
The new-for-’07 rolling starts finally produced the big first corner shunt they had threatened to. Gabriele Tarquini, Rob Huff, Felix Porteiro, Allessandro Zanardi and Roberto Colciago were all eliminated.
After a safety car restart Thompson cruised away into a lead he was never going to lose. Indeed the entire top six held position until the end.
Luca Rangoni and Jorg Muller quickly vaulted up to seventh and eighth but Farfus languished in 17th in the early stages.
The Brazilian battled through the field to launch a bold bid for ninth with two laps to go. But he only succeeded in crashing out along with Sergio Hernandez, Stefano D’Aste and Tom Coronel. This promoted Alain Menu to ninth.
Despite struggling with 45kg of ballast Andy Priaulx tried hard to pass the Seats of Yvan Muller (third) and Jordi Gene (fourth), but had to settle for fifth.
Nicola Larini underlined Chevrolet’s pace with second place, but it will be Jorg Muller on pole for race two.