At Thorndike, Ryan Rice scored the game- winning goal on an assist from Yanni Rakis with 4.9 seconds remaining in the second overtime to lift Belfast to victory.
Mount View’s Kyle Crowell scored with a minute left in the second half to send the game to overtime.
Rakis finished the game with three goals and two assists. Tyler Baker also scored a goal while Jacob Levangie-Thompson added two assists.
Trevor Diemer and Lorenzo Milani each converted a penalty kick for Mount View. Jack Simpson added a second-half goal from a James Philbrick assist and Crowell’s goal came on a Milani assist.
Mount View goalkeeper Mikey Hustus made 11 saves on 23 shots.
Belfast goalkeepers Sam Kulikowski and Tyler Baker combined to make 11 saves on 25 shots.