Lucas Mahias (Kawasaki Puccetti Racing) won a thrilling last lap battle with Isaac Vinales (Kallio Racing Yamaha) to take his first Kawasaki race win, and in front of his home crowd.
Another Kawasaki rider, Ayrton Badovini (Team Pedercini Racing Kawasaki) took the final podium place in a frantic and shortened 12-lap contest.
The start of the WorldSSP race had hardly got underway before a red flag was thrown, after a lurid crash between three riders, Bau, Calero and Fuglio, all of whom went to hospital for further checks.
The restart, over 12 laps, got underway again in warm sunshine, with Jules Cluzel (GMT94 Yamaha) leading off. Pole man Kyle Smith (Team Pedercini Racing Kawasaki) and his team-mate Ayrton Badovini were also in the mix.
A high highside crash from long-time championship leader Randy Krummenacher (BARDAHL Evan Bros. WorldSSP Yamaha) seemed to gift race leader Federico Caricasulo (BARDAHL Evan Bros. WorldSSP Yamaha) the championship lead but the Italian rider fell himself. He restarted, set about trying to gain some points back, only to fall again in the fast first right-hander.
After the exit of the two main championship contenders, Cluzel led the race, until he was swamped by both Vinales and Mahias, with Badovini also dining in to take third.
An eight rider leading fight was in evidence on lap nine of the rescheduled 12 lap race, with Smith and Thomas Gradinger (Kallio Racing Yamaha) slowly dropping back to leave a top six.
Mahias and Vinales broke away, followed by the other four, and their last lap fight was a classic. Vinales looked to have won with a late pass into the final chicane entry, only for Mahias to come across the take the victory.
Behind the top three Raffaele De Rosa (MV Agusta Reparto Corse) was fourth, Hikari Okubo (Kawasaki Puccetti Racing) fifth, and one time favourite Cluzel sixth.
Corentin Perolari (GMT94 Yamaha) placed seventh, Gradinger eighth, pole man Smith ninth and Peter Sebestyen (CIA Landlord Insurance Honda) rounded out the top ten.
In the championship points Krummenacher has 193, Caricasulo 183, Cluzel 155 and Mahias 123. Two rounds to go.