The host Titans scored in the eighth minute of the game and held the 1-0 lead until scoring on a header at 58:01.
Oshkosh's third goal came on a direct kick with six minute to play in the game.
The Titans had 10 shots on goal to the Pipers' three.
The Pipers drop to 2-3 overall. They stay in Oshkosh to play Augustana (S.D.) tomorrow, Sunday, September 13, at 12:30 p.m.