Huff came through in 25:17.714 after the 13 laps with team-mates Yvan Muller and Alain Menu completing the top three places.
As a result of the victory, the Englishman stretched his championship lead by a further seven points with Chevrolet utterly dominant.
“It was a fantastic weekend for me, especially after the qualifying session I had yesterday,” Huff said.
“I was very disappointed with qualifying, but today my car was great. Obviously I feel pretty happy to go to Macau as the championship leader. That circuit has also been very good to me in the last four years.
“Anything can happen there (Macau), but our car is very strong on street circuits. I’m very excited.”
The three Chevrolet cars were followed by Tom Coronel, Stefano D’Aste and Mehdi Bennani, who finished in fourth, fifth and sixth, respectively.
Gabriele Tarquini was classified seventh, ahead of Colin Turkington who managed prevail after a race-long battle with Tom Boardman, Alberto Cerqui and Tiago Monteiro.
Earlier on Sunday, Alain Menu had won race one from Huff in a time of 25:12.369, with D'Aste third.