Lannon completed a weekend sweep of Oconomowoc in the Land O'Lakes Western Division playoffs and emerged with the league title aftera n 18-6 victory over the Five O's on Sunday at Roosevelt Field.
The game lasted seven innings, terminated on account of the 12-run mercy rule.
The Stonemen, who needed a win Saturday to force Sunday's winner-take-all matchup, picked up four RBIs from Scott Doffek, who also initiated a pair of difficult double plays in the field.
Ron Kozlowski went 4-for-5 with three runs scored, Scott Hagen went 3-for-4, and the team finished with 16 hits overall. Mark Fiala earned the win in relief.
Chandler Ziemann went 3-for-4 with two runs scored for Cooney, and Derek Nelson went 3-for-3 with two RBIs.
Lannon will compete in the LOL Grand Championships next weekend, facing the North winner Saturday and the Southwest winner Sunday.