The Windsor Spitfires are now facing elimination after losing 4-3 on home ice to the Flint Firebirds on Sunday night.
Windsor dominated possession and outshot Flint by a 45-19 margin, but saw their early 2-0 lead vanish as the Firebirds battled their way through on the road.
Flint now leads the best-of-7 OHL Western Conference final 3-2 as the series shifts back to Michigan.
Captain Will Cuylle and leading scorer Wyatt Johnston each had a goal and an assist in the loss.
Game 6 is scheduled for Tuesday night in Flint with puck drop at 7:00 p.m. and the AM800 pre-game show getting underway at 6:45 p.m.