At East Sullivan, the Tigers jumped out to a 19-6 lead at the end of the first quarter en route to the victory.
Savana Turner paced the Tigers with 20 points, Jordan Merchant added 16 and Taylor Davis netted eight.
Brianna Bires scored 12 points to lead the Golden Bucks and Deb Wight put in nine.
Sumner 19 27 41 53
Bucksport 6 16 24 38