Bruce Anstey sealed his 12th Ulster Grand Prix win in the shortened opening Supersport race at Dundrod, which was red-flagged on lap four.
Olie Linsdell came off at Joey's, causing the stoppage, but was later reported to have no serious injuries.
With four of the six laps completed, the race was declared a result, giving Flying Kiwi Anstey the win on the Valvoline Padgetts Honda over Ian Hutchinson (Came BPT Yamaha).
The podium was completed by Manx rider Conor Cummins, who narrowly claimed third on the Valvoline Padgetts Honda ahead of Dean Harrison (Silicone Engineering Kawasaki).
After a slight delay with light rain beginning to fall around the course, pole man Anstey took the race by the scruff of the neck and made his experience count in the patchy conditions to quickly open a gap of two seconds over Hutchinson.
However, as the race progressed, the roads rapidly began to dry out and Hutchinson was on the charge, visibly reducing Anstey's lead.
On lap four, the gap was down to 0.8 seconds but Yorkshire rider Hutchy was left to reflect on what might have been when the red flags went out. Dan Kneen finished fifth (Mar-Train Yamaha) ahead of William Dunlop on the IC Racing Yamaha.
Peter Hickman (Trooper Beer Kawasaki) and southern Irish rider Derek McGee (Yamaha) were the top eight. Michael Dunlop was a retirement on his MD Racing Yamaha.