The overtime score made a winner out of Philadelphia goaltender Martin Biron in his debut with the team. Biron, obtained Tuesday from Buffalo for a second-round draft pick, made 34 saves.

Biron's biggest save came late in the overtime period when he stopped a shot despite being screened. The rebound went to Philadelphia's Sami Kapanen, who hit Upshall with the pass that led to the winning goal.

Philadelphia halted a five-game losing streak.

Boston let an early two-goal lead get away and lost for the third time in a row following four straight victories. Tim Thomas made 51 saves as the Flyers got off 55 shots -- a franchise record for a road game.