Simon Skillicorn won Saturday's Glen Mona Horse shoe by over four minutes.
Tom Cringle, who is his nearest rival in the league this year, was second, and Ian Gale was third.
Cal Partington claimed the women's race ahead of last year's winner Rose Hooton. Bridget Kaneen was third.
David Mullarkey selected by Great Britain for road running championships
Island athletics star heading for Denmark
Harris wins opening qualifying round at US Open
He beat Gonzalo Beuno by two sets
Michael Dunlop wins Senior Classic TT
Seven Mountain Course victories for Ballymoney man in 2026
Johnny Stewart wins Senior Manx Grand Prix
First rider to ever win four MGP races in a single event