Lajeunesse topped Tecumseh Vista 4-3 to win the WECSSAA single 'A' final.
The Royals won the final series two games to one.
Captain Phil Nadeau scored twice including the game winner.
He says "If it wasn't for my teammates we wouldn't be here. We all work together as a group and we pulled off something incredible."
Nadeau also say "We didn't expect this kind of crowd here. We were just hoping to get a fan bus, but this ended up happening. It's incredible."
Also Belle River won the Tier 1 title, by blanking Amherst 4-0. Patrick Timpany earned the shutout.