Tiago Monteiro completed the podium despite cruising across the line, with works Honda team-mate Gabriele Tarquini - whom he picked off at half distance - missing out by just seven tenths of a second.
Newly-crowned champion Yvan Muller and race one winner Norbert Michelisz were both victims of the starting melee.
The pair made contact in the squeeze away from the line, with Muller hitting the barriers and Michelisz suffering a race-ending puncture.
That was in contrast to front-row men Bennani and Coronel, who maintained their advantage off the grid and began pulling away from the chasing pack even while squabbling over the lead in their BMWs.
Coronel looked to Bennani's inside at Turn 1 almost without fail over the first half of the race, only for the Moroccan to stick it out around the outside each time and claim the line for Turn 2.
That finally reversed on lap 17 however as Coronel this time lunged at the second right-hander, catching Bennani by surprise and allowing the Dutchman to slip into a lead he would convert for his fourth WTCC win.
Monteiro was likewise able to pull away from Tarquini, although the gap was all but wiped out at the flag as he eased off.
Tarquini held on to fourth ahead of Chevrolet pair James Nash and Tom Chilton, while Charles Ng got the better of 2012 champion Ron Huff in a fantastic battle for seventh.
It was even more fraught behind as Alex MacDowall, James Thompson, Marc Basseng, Stefano D'Aste. Darryl O'Young and Fernando Monje squabbled over the final points-paying positions.
Thompson held ninth going into the final lap, but was nudged out by Basseng and ended up dropping to 13th, just ahead of MacDowall.
D'Aste beat fellow BMW man O'Young to 10th by just 0.1s.
Masaki Kano, called up to replace the injured Franz Engstler, was the best of the Asian newcomers in 16th.
Results - 26 laps:Pos Driver Team/Car Time/Gap 1. Tom Coronel ROAL BMW 23m56.929s 2. Mehdi Bennani Proteam BMW +2.259s 3. Tiago Monteiro Honda +9.935s 4. Gabriele Tarquini Honda +10.732s 5. James Nash Bamboo Chevrolet +11.438s 6. Tom Chilton RML Chevrolet +11.802s 7. Charles Ng Engstler BMW +13.762s 8. Rob Huff Munnich SEAT +14.088s 9. Marc Basseng Munnich SEAT +23.300s 10. Stefano D'Aste PB BMW +23.564s 11. Darryl O'Young ROAL BMW +23.753s 12. James Thompson Lada +23.780s 13. Alex MacDowall Bamboo Chevrolet +24.249s 14. Fernando Monje Campos SEAT +24.497s 15. Rene Munnich Munnich SEAT +24.739s 16. Masaki Kano Engstler BMW +26.576s 17. Yukinori Tanguchi Wiechers BMW +36.768s 18. Jeronimo Badaraco Son Veng Chevrolet +54.197s 19. Mikhail Kozlovskiy Lada +1 lap 20. Kin Veng Ng China Dragon Chevrolet +1 lap 21. Henry Ho Engstler BMW +3 laps Retirements: Takuya Izawa Honda 19 laps Tom Boardman Special Tuning SEAT 16 laps Hiroki Yoshimoto Nika Chevrolet 14 laps Pepe Oriola Tuenti Chevrolet 13 laps Ka Lok Mak RPM BMW 10 laps Felipe de Souza China Dragon Chevrolet 1 lap Norbert Michelisz Zengo Honda 1 lap Yvan Muller RML Chevrolet 0 laps
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