At Waldoboro, Julie Ennamorti scored with 3:56 left in the first overtime, lifting the Panthers to victory.
Emily Leach and Alanna Vose set up the game-winner, helping Medomak Valley erase its second, one-goal deficit.
Sammie Griffin scored on a rebound and Mallory Conary converted a Vose assist for the Panthers. Amanda Hendrickson-Belloguet made 10 saves on 12 shots.
Pilar Elias scored both goals for Winslow. Elizabeth Ferry made six saves on 24 shots.