Ian Ryan's side went down 2-0 to Treaty United.
Athlone fell to a second defeat in three games in the League of Ireland on Friday night.
Ian Ryan's side went down 2-0 to Treaty United in Markets Field after goals from former Town defender Ben Feeney, and a Cian Curtis penalty.
The result leaves Athlone in third place in the standings after six games, while Treaty remain bottom of the standings after getting their first win of the campaign.
The Midlanders return to action against league leaders Cork in Turner's Cross on Friday.
Full Interview: Portarlington Footballer Ronan Coffey
Full Interview: The Down's Manager Dermot Power
St Brigid's And St Joseph's Aiming To Reach Leinster Semi-Finals
Ballinagar And Milltown To Meet In Leinster Intermediate Quarter-Final
Ronan Coffey Praises Portarlington’s Young Guns Ahead Of Leinster Quarter-Final
Mauricio Pochettino Set To Be Appointed Manchester United Manager
Darragh Murray Named In Irish Squad For Fiji Clash
Portlaoise Panthers Aiming To Bounce Back In Division One
Portarlington On The Road In Leinster
The Down's Building Towards Leinster Football Quarter-Final
Laois Provisional League Fixtures Revealed
The Harps Manager Praises His Sides Efforts In Leinster
Buccaneers Claim Back To Back AIL Wins
Kilcormac Killoughey Captain Full Of Praise For Goalkeeper
Lough Lene Gaels Suffer Late Heartbreak In Leinster Quarter-Final
Crookedwood Win Leinster Junior Camogie Title
Conor Slevin Wins Dramatic Leinster Quarter-Final For Kilcormac Killoughey
Ireland Secure Comfortable Win Over Argentina
Kilcormac Killoughey Seal Win But Heartbreak For Lough Lene Gaels And The Harps