Yesterday's racing at the Dundrod 150 was delayed and later shortened by the damp and misty weather.
Added to that, some races ended early due to red flag incidents.
James Coward took the honours in the opening National Race, in which the first seven crossed the finish line before a red flag halted proceedings.
A serious incident at Flobog saw Skerries rider Derek Costello taken to hospital.
The Club said: 'He has received treatment for trauma to the head. This went as planned. He will be under observation for the next 24 hours'.
Other winners were Ian Lougher in the 125cc, Andy Farrell in the 400cc, Wayne Hamilton in the Supertwins, Ollie Linsdell in the Classic 500cc and Peter Wakefield in the Classic 250cc.
With the weather closing in, the feature Superbike Race was brought forward but was abandoned at the end of the opening lap, with the mist causing major visibility problems.