The Barrie Colts comeback falls one goal short.
London salvaged a win in Game 6 Saturday night after blowing an early lead.
Ryan Rupert's second goal of the game 90 seconds into the first overtime helped the Knights edge the Colts 5-4 to tie the OHL championship final at 3.
London built a 4-0 lead on goals by Brett Welychka, Tommy Hughes, Bo Horvat, and Rupert.
Andreas Athanasiou got the first Barrie goal five minutes into the third period.
Erik Bradford scored with 5 minutes left in the period to cut London's lead down to 4-2.
30 seconds later, Mitchell Theoret would trim that lead to 1 with his goal.
Then with the goalie on the bench for an extra attacker, Theoret's second goal of the game tied it up at 4-4 with 41 seconds left in regulation.
Theoret (2 goals, 1 assist) and Athanasiou (1 goal, 2 assists) each finished with 3 points in the game.
Max Domi had 3 assists for the Knights.
Mathias Niederberger stopped 18 of 22 shots for the Colts and was replaced by Alex Fotinos to start the third period.
Jake Patterson made 23 saves for the Knights.
The seventh and deciding game goes Monday night in London.
The winner of this series will represent the OHL in the Memorial Cup tournament in Saskatoon.
Click on audio to hear a game recap and post-game comments from Knights Forward Ryan Rupert and Colts Forward Mitchell Theoret.