Playing their second game in as many days, the Owen Sound Attack fell behind early but rallied from a three goal deficit only to lose in overtime. Brady Hinz scored the game winner for Peterborough less than two minutes into the final frame and the Petes won it 4-3.
Adam Timleck scored a natural hat trick in the first and second periods, putting the Petes up 3-0.
Griffin Wilson put the Attack on the board with 73 seconds left in the middle frame.
Kaleb Pearson scored just 56 seconds into the third and Maksim Sushko had the equalizer at 8:52 to send the game into overtime.
Brady Lyle had two assits for the Attack in the loss.
The Attack are back in action on Saturday when they host Flint.