Menu led home yet another 1-2-3 for Chevrolet, with his Cruze followed by team-mates Yvan Muller and Rob Huff.
Alex MacDowall completed Chevrolet’s hat trick by finishing fifth overall and first in the Yokohama Trophy in his bamboo-engineering Cruze.
The top positions were decided immediately after the start, when Muller kept Huff at bay resisting a contact into turn two, while Gabriele Tarquini overtook MacDowall for fourth.
"It was a good weekend. Once again the Chevrolet was the best car, and the key was pole position," said Menu.
"Against people like Yvan and Rob you cannot afford to make mistakes as they are ready to overtake. On top of this I had to be gentle with my front tyres.
"Yvan and Rob never gave up and I had to push. It was very very tricky. It was a hard work. For the championship is going to very difficult. 38 points to recover are a lot with only four races left. But I won’t give up."
Race one results:
1. Alain MENU CHE Chevrolet Cruze 1.6T 23:44.880
2. Yvan MULLER FRA Chevrolet Cruze 1.6T 23:45.692
3. Robert HUFF GBR Chevrolet Cruze 1.6T 23:46.299
4. Gabriele TARQUINI ITA SEAT Leon WTCC 23:58.708
5. Alex MACDOWALL GBR Chevrolet Cruze 1.6T 23:59.153
6. Aleksei DUDUKALO RUS SEAT Leon WTCC 24:04.524
7. Tom CORONEL NLD BMW 320 TC 24:04.750
8. Pepe ORIOLA ESP SEAT Leon WTCC 24:05.295
9. Stefano D'ASTE ITA BMW 320 TC 24:05.557
10. Tiago MONTEIRO PRT Honda Civic S2000TC 24:06.164