Guernsey took both the men's and women's titles
Guernsey's bowlers scored the double over Jersey by winning the Inter-insular men's and women's titles.
Despite losing four out of their six games the men's team scored more points than their Jersey counterparts and took the overall victory 122 points to 103.
The women's title was closer with Guernsey winning by two points 103-101.
Guernsey men's captain Steve Desperques told BBC Guernsey: "There's been some excellent bowls played, it's pleasing to see youngsters on both sides."
Alongside the younger players was 83-year-old Ken Swanton who earned his first cap for Jersey on the day.
Swanton said although it has been a long wait it was an honour to represent his island: "I started bowling when I was seven, crown green in the 1930s and I've just been recognised.
"You enjoy these things and I've always been one for sport, to have this at 83 is a feather in my cap and I'm as pleased as punch."