Windsor's 13-game point-streak came to an end after at 6-3 loss to the Knights in London Friday night.
London jumped out to a 3-0 lead on goals from Connor McMichael, Nathan Dunkley and Antonio Stranges.
Windsor finally got on the board to start the third period on a goal from Daniel D'Amico, but Liam Foudy, Cole Tymkin and Luke Evangelista answered for London to make it 6-1.
Connor Corcoran and Chris Playfair both scored to make it 6-3 in the final minutes of the third, but London held on for their fifth straight win.
Kari Piiroinen made 34 saves in a losing effort.
It's the Spitfires first regulation loss since Oct. 11.
The Spitfires hold on to first place in the OHL's West Division after Saginaw was defeated 6-2 by the Guelph Storm.
Windsor returns to the WFCU Centre Saturday to host the Niagara Ice Dogs.
Puck drops at 7pm — tune into AM800 for all the action.