Coming into the last game of the regular season, Lancaster was just a win behind the Lakers on the ladder with a better percentage.
Nagambie needed a win at Avenel Recreation Reserve against its local rival to secure top spot.
With Avenel’s finals chances already put to bed the previous week, the Lakers would have been hoping for a home side with less drive rather than one playing without pressure or fear.
Nagambie calmed the nerves of its fans as it got off to a blistering start, kicking six goals and five behinds in the first quarter while holding the Swans to two points.
It was more of the same in the second spell as the Lakers added four more goals to their tally, but it could have been more if the side was more efficient in front of goal.
The Swans got their first majors of the game before half-time but trailed by 52 at the break.
Nagambie looked like a side wanting to make a statement as it once again held the home side to two points in the third quarter while piling on five goals.
The Swans stepped up in the last quarter, almost going goal for goal with the visitors, but the Lakers confirmed themselves as the best outfit in the league with a 19.21 (135) to 5.10 (40) victory.
Tom Barnes starred for the visitors with five goals, while the Swans’ best performer was vice-captain Braydon Avola.
At Central Park Recreation Reserve, the Eagles ran riot against Merrigum and claimed a 15.21 (111) to 5.5 (35) win.
Shepparton East was made to wait to see if the result was enough to clinch third place as Murchison-Toolamba had a Sunday fixture against Girgarre.
After a week of rest, Nagambie will face Lancaster at Stanhope Recreation Reserve for a place in the grand final.