The Knights got out to a 3-0 lead and held on for a 4-2 victory and sweep of the West final.
Olli Maatta continued his hot streak for the Knights scoring a shorthanded goal to put London up 1-0 late in the first.
In the second the Knights capitalized on the power play for the first time of the series when Ryan Rupert scored his fifth of the playoffs. Seth Griffith added another power play goal in the final five minutes of the third to go ahead 3-0 with just 20 minutes to play.
Brett Thomson broke the goose-egg for the Rangers with their season on the line scoring six minutes into the third period. Cody Sol's slap-shot cut the Knights lead to one with more than five minutes to play in the third. With Gibson pulled from the Rangers net in favour of an extra attacker, Seth Griffith stole the puck at his blue-line and fired it down the ice into the empty net ensuring a Knights win. Watch the highlights