Top Speed Up finisher and highest placing Italian at his home Grand Prix was NGM Mobile Racing's Simone Corsi, who took seventh just ahead of his team-mate Alex De Angelis in eighth who fell down the order after clashing with Xavier Simeon, who he caused to crash out of the race.
The top ten was completed by Swiss riders Tom Luthi in ninth for Interwetten and Dominique Aegerter in tenth for Technomag carXpert.
Former champion Toni Elias grabbed eleventh for the Blusens Avintia team, while Marcel Schrotter found himself pushed back quickly from his third place start and finished twelfth for the Desguaces LA Torre SAG team.
Tito Rabat fought back to 13th after being forced wide on his Pons Tuenti bike early in the race by a battle between Simeon and Kallio.
The final points were taken by rookie and last years Moto3 champion Sandro Cortese for Dynavolt Intact GP in 14th and Technomag carXpert rider Randy Krummenacher in 15th.
Takaaki Nakagami had held the lead early on but came under pressure and was passed by both Redding and Terol. He crashed his Italtrans into the gravel while trying to hold onto fourth place.
The other Brits in the championship continued to struggle in the intermediate class with Kyle Smith finishing in 21st for the Blusens Avintia team just ahead of his fellow countryman Danny Kent who was 22nd for Tech 3.