The top two teams in the GOJHL's Western Conference are facing elimination following losses Wednesday night.
Leamington took a 3-2 series lead over first place LaSalle with a 3-2 victory, while the London Nationals lead Chatham 3-1 after a convincing 8-2 win in game four.
In London, the game was tied 2-2 midway through the second period, before the Nationals exploded for six unanswered goals to take control of the game, and the series. Brandon Glover led the way with a four point effort, while captain Austin Kemp and defenceman Quinn Lenihan each had a goal and two assists.
In LaSalle, the Vipers lost to the Flyers despite out shooting Leamington 41-23. Connor Meyerink made 39 saves in net for the visitors.
Both series continue Thursday night, with London and Leamington both needing a win to advance to the Western Conference Final, Chatham and LaSalle will be looking to extend their playoff lives.
London won the Bill Weir Championship last season, and eventually lost to Caledonia in the Sutherland Cup Finals.