Michael Dunlop ended the Irish road racing season on a high by securing victories in the Open and Grand Final events at Killalane, near Dublin.
The 26-year-old passed early leader Derek Sheils in the Open race and ultimately enjoyed a five-second advantage at the chequered flag.
William Dunlop's third place finish was enough to clinch the Irish Superbike title for the first time.
Michael won the Grand Final by almost 12.5 seconds from Derek McGee.
The MD Racing BMW rider assumed the lead after early pace setter Sheils retired, while William finished third on his Tyco BMW.
Michael successfully retained the crown he won in 2014.
William Dunlop ended the season unbeaten in the Supersport class by taking the flag on the Chris Dowd/Ivan Curran Racing Yamaha.
The 30-year-old, who clinched the championship at Armoy, held off McGee to win by 1.5 seconds, with Southern 100 winner Seamus Elliott eight seconds down on Dunlop in third.