Evan Bouchard scored the game winner 3:28 into overtime to give London a 3-2 win over Erie.
The Knights were down 2-0 after the first period when Cole Tymkin put them on the board at 3:31 of the second. Liam Foudy tied the game just before the midway point of the third.
Joseph Raaymakers stopped 33 shots in the win. Anand Oberoi made 37 saves for the Otters.
Bouchard led the Knights with a goal and an assist.
The Knights are third in the Midwest with 34 points. Erie is in last place in the Division with 26.