Derek McGee completed a hat-trick a the KDM Hire Cookstown 100 after being declared the winner of the feature Superbike race, which was red-flagged twice.
McGee held a slender advantage of only 0.092 seconds from Derek Sheils after three laps when the race was halted, with Adam McLean and Michael Sweeney also right in the mix.
Paul Jordan finished fifth on his 600 Yamaha ahead of Neil Kernohan.
It was a disappointing end to the day, although fortunately the riders involved in the red flag incidents were reported to have escaped serious injury.
Adam McLean sealed a popular victory in the shortened Supersport race, which was called a result after four laps.
The McAdoo Racing Kawasaki rider was setting the pace at the front from Derek McGee and Paul Jordan when the red flags came out, reportedly due to debris blown onto the course by the wind.
McLean was declared the winner by 0.3 seconds from McGee, with Magherafelt man Jordan a further half-a-second back in third on Alistair Russell’s Yamaha R6.
Derek Sheils took fourth on the Roadhouse Macau Racing Yamaha ahead of Michael Sweeney and Neil Kernohan.
Sheils made it six Superbike wins on the spin at the Cookstown 100 as he won the Open A race on the new-look Burrows Engineering/RK Racing Suzuki.
Postponed from Friday evening, he swept into the lead of the race ahead of McLean and McGee with nothing between the top three.
McGee made a pass on McLean to move into second place, but the McAdoo Racing Kawasaki rider soon returned the favour. As they traded places, Sheils opened a lead of six-tenths-of-a-second after three laps.
As the race settled down, Sheils extended his lead to 1.7 seconds over McLean, who was holding off McGee in third as the top three pulled a gap over the chasing pack.
The Dublin rider was now in his groove and he opened a cushion of 3.3 seconds over McLean on the penultimate lap to put the race to bed, maintaining his winning streak in the class since 2016.
At the finish, Sheils’ winning margin remained the same, with McLean taking the runner-up spot half-a-second ahead of McGee. Thomas Maxwell, Paul Williams and Neil Kernohan were the top six.
Earlier, McGee sealed a double as he won the Supertwin race on his Jason McCaw-backed KMR Kawasaki.
He had to dig deep to get the better of young gun Adam McLean, who pushed him all the way on the McAdoo Racing Kawasaki.
The lead changed hands on numerous occasions, but it was McGee who prevailed by half-a-second at the line, with Skerries man Michael Sweeney only six-tenths back on McLean.
McGee also made a winning debut on the Faraldo Racing Honda in the Moto3 race. The triple Irish champion led throughout on his ex-Moto3 Grand Prix bike, stretching his lead on the patchy roads and eventually taking the flag by 9.5 seconds from road racing stalwart Nigel Moore.
Kevin Fitzpatrick claimed third, a further 15 seconds in arrears, with Paul Gartland finishing the race in fourth place.
The Junior Support race went to Eoin O’Siochru, who snatched victory from Vincent Brennen by 2.2 seconds. Dominic Cottrell rounded out the top three.
Barry Davidson made a winning start to 2019 in the Junior Classic race, winning by 4.8 seconds from Ed Manly. Nigel Moore was back on the rostrum following his runner-up finish in the earlier Moto3 race, taking third position this time.