At Bar Harbor, the Trojans built a 10-point halftime lead and held on to beat the Wildcats.
Ben Walls led the way for Mount Desert Island with 14 points and Adam Gray posted eight points.
Jonah Stephenson scored a game-high 20 points to propel Presque Isle. Ben Nickerson added 11 points.
PI 5 19 31 48
MDI 14 29 36 49