Simon, the pre-season favourite who finished second in the first two rounds, now leads the world championship by 5.5 points from Smith.
After his early spill, Terol mounted an impressive recovery to reach fifth on lap 18… when he fell again. The Jack and Jones Aprilia rider once again rejoined the action to cross the line in ninth.
Former championship leader Iannone, who began the race just 23rd on the grid for ISPA Aprilia, fell on the very first lap, leaving him 31st and last. Aided by accidents ahead, the Italian reached the chequered flag in seventh.
Race result - Le Mans:
1. Simon (Aprilia)
2. Folger (Aprilia) +27.084sec
3. Gadea (Aprilia) +30.916sec
4. Smith (Aprilia) +31.530sec
5. Nakagami (Aprilia) +1min 9.235sec
6. Aegerter (Derbi) +1min 12.223sec
7. Iannone (Aprilia) +1min 13.663sec
8. Vazquez (Derbi) +1min 19.912sec
9. Terol (Aprilia) +1min 40.036sec
10. Zanetti (Aprilia) +1min 42.700sec
DNF Redding (Aprilia)
DNF Webb (Aprilia)
DNS Hoyle (Haojue)