Forecast rain and high winds turned the middleweight race at the Australian Grand Prix venue into a crapshoot, with no fewer than 10 riders falling before the race was called after just nine laps of the scheduled 23.
The drama began before the race even got underway as championship leader Pedro Acosta crashed his Ajo Kalex on the sighting lap, consigning himself to a back-of-the-grid start.
Speed Up rider Fermin Aldeguer led initially from pole as team-mate Alonso Lopez became the first casualty of the leading group, crashing out of second on the very first lap.
Sergio Garcia (Pons) assumed the lead at the end of the opening lap from Filip Salac, (Gresini) but both riders would hit the deck on the fourth lap of the race just moments apart.
That promoted Marc VDS Kalex man Arbolino into a lead he wouldn't lose, and when Jake Dixon (Aspar) became the latest victim of the awful conditions on lap five, Arbolino found himself with a massive 12s advantage over Aldeguer.
The Italian had stretched that out to 15s when the red flags came out just after the leaders had completed the ninth lap, and shortly after it was announced the race would not be restarted and half-points awarded due to two-thirds distance not being reached.
Arbolino, who amusingly suggested in parc ferme that double points should be awarded due to the awful conditions, closes to 56 points behind Acosta, who recovered from his sighting lap tumble to finish ninth, helped by the high attrition rate.
Aron Canet (Pons) managed to pass Aldeguer on what turned out to be the final lap to grab second, with Jeremy Alcoba (Gresini) and Joe Roberts (Italtrans) completing the top five.
In the earlier Moto3 race, held in wet but less treacherous conditions, Deniz Oncu executed a perfectly-judged last lap pass on Ayumu Sasaki to score his third victory of the season.
Source: Autosport