After the frantic first few laps, the order at the front stabilised with West in class of his own up front, holding a 4.4secs lead over Campetella team-mates Guintoli and Battaini.
By the midway point, West's quest for a first GP victory was looking slightly less secure as new second placed man Battaini took some time from him, only for the Aussie to respond as the advantage see-sawed from lap to lap.
Guintoli had now been dropped by Battaini and was 6secs further back in third, but was five seconds ahead of the first real fight between Poggiali, Porto and Rolfo.
Into the final three laps and West had pinned his advantage against Battaini to over 6secs, as the #14 continued his faultless ride to victory on what was now a slowly drying track - but Battaini wasn't done yet...
The Italian veteran sent shockwaves into West's Abruzzo garage as he stole 2secs over Ant by the start of the penultimate lap, and looked to have a shot of victory. However, West's nerve held and he would take the flag - and a breakthrough victory - by 2.9secs.
Guintoli completed a fantastic day for the Campetella team with third behind his team-mate, while Poggiali collected vital championship points with fourth ahead of the Hondas of Porto and Rolfo. Elias would finish a lap down in 18th.
Full results to follow...