Tallygaroopna needs to defeat Stanhope on Saturday to lock up third on the ladder after an agonising two-point loss to Avenel.
The Redlegs were 11 points ahead at half-time, but the Swans are a quality opposition and finished better in the second half.
It meant it was a second loss in as many weeks to a grand finalist from last year after being right in the game against Nagambie before falling short.
For the Swans, they will enter the finals as one of the form sides with 10 wins from their past 12 games.
The teams could be playing each other again in less than two weeks, depending on the final round result between the Redlegs and Stanhope.
Avenel playing coach Don Stirling said the win would give his team confidence heading into the finals.
‘‘I’m really happy with that because they (Tallygaroopna) jumped out of the blocks early,’’ Stirling said.
‘‘It was a good challenge for us to show a bit of character and get ourselves back in the game.
‘‘A win like that gives us a lot of belief because we’ll be playing the winner of the Tally-Stanhope game in the first week of finals.
‘‘If Tally wins, we know we can beat them and if we’re playing Stanhope, we’ll have confidence for that as well.’’
Scott Tyers had another excellent outing down back, always getting the job on the best forwards.
Michael Morgan, Paul Arandt, Michael McKenzie, Lachlan Drummond and Max Lawrence were outstanding.
Michael Berry and Grant Hateley played in the reserves, highlighting the Swans’ depth and potential ahead of another finals campaign.
Tallygaroopna coach Chris Earles said his side won most areas of the game, but was disappointed to be on the wrong end of the result.
‘‘We’ve got next week to redeem ourselves and keep that top three spot,’’ Earles said.
‘‘We lost a game we should’ve won, we had basically every area on the ground covered except one and things just went against us.’’
Doug Wren and Tyson Sidebottom put in a power of work in the midfield running against Stirling and Morgan, while Stu McFarlane had one of his best games.
Sam Muggleton and Jai Simmie popped up with three goals each, while Kane Handley and Cameron Holdsworth played well.
Meanwhile, the Redlegs will be looking for a new coach next season, with Earles announcing to the club during the week that this season would be his last in charge.
Earles, who took over a few games into the 2014 season, believed it was the right time to let the club prepare for next season and had to focus on his life outside football.