The KDM Hire Cookstown 100 was abandoned on Saturday following a series of crashes.
No serious injuries were reported but with time running out, Clerk of the Course Francis Everard made the decision to call it quits with a number of races still to run, including the feature Cookstown 100 finale.
Wet weather added to the difficulties faced by the organisers at the County Tyrone meeting and a raft of incidents at Braeside corner in particular caused concern, with two separate incidents occurring in both the Supertwins and Senior Support races.
Earlier, Derek Sheils won the Open A Superbike race on the Burrows Engineering Suzuki on corrected time after starting from the B Group.
Michael Dunlop, who won the Supersport Invitation race on his Honda, was second on the Tyco BMW.
James Cowton and Adam McLean celebrated a one-two for local team McAdoo Racing in the Supersport A race, which was declared a result after four laps.
McLean later won the Supertwins race from newcomers Daniel Mettam and Davey Todd, while Derek McGee was victorious in the Moto3 race on the Joey’s Bar Honda.