Midfielder Barry McNulty was a powerhouse, scoring 1-06, as Leitrim defeated Sligo for the first time in the Connacht GAA Football Senior Championship since 2011.
Leitrim, who also goaled through Keith Keegan and Ryan O'Rourke, were 10 points clear at one stage in the second-half and managed to withstand a determined Sligo comeback that whittled the deficit down to a point in wintry conditions.
Sligo overcame Leitrim by nine points, 0-15 to 0-6, when the sides last met in Connacht – that was also a quarter-final in 2024 that Sligo, then managed by Tony McEntee, dominated.
Leitrim, who last beat Sligo in a Connacht senior fixture 15 years ago, a 1-10 to 0-10 fixture played at Markievicz Park, came into this game on the back of finishing seventh in Division Four of the Allianz Football League – their record of three losses and four wins was matched by Sligo who finished fifth in Division Three.
This was a first championship fixture for Sligo's joint-managers, Eamonn O’Hara and Dessie Sloyan, while it was a second campaign for Leitrim boss Steven Poacher, the Down native.
Wind-assisted Leitrim opened the scoring with a point from Tom Prior, with Lee Deignan replying for Sligo.
Barry McNulty’s fifth minute free put Leitrim back in front, 0-2 to 0-1, but then Sligo took over with five points without reply - a scoring surge that included fine scores from Niall Murphy, Lee Deignan and Luke Towey.
Leitrim bounced back with a 16th minute goal from the outstanding Barry McNulty, who lobbed Sligo goalkeeper Aidan Devaney from Oisin McLoughlin’s pass.
Although Sligo hit back with another point from Lee Deignan - his third - this 18th minute score was Sligo’s final score of the first-half.
Wind-assisted Leitrim took charge and Barry McNulty hit an inspirational two-pointer.
Leitrim’s second goal came from wing-back Keith Keegan, who seized on a breaking ball in Sligo’s goalmouth, with the visitors full value for their 2-7 to 0-7 interval lead.
Sligo made a brisk start to the second-half and, backed by the elements, they tacked on points from Lee Deignan, their most prominent forward.
But the home side were stunned when falling 10 points down, 3-11 to 0-10, by the 47th minute.
Leitrim captain Ryan O'Rourke fired home the winners' third goal in the phase that immediately followed Sligo goalkeeper Aidan Devaney's thwarting of Oisin McLoughlin's goalbound effort.
Sligo were on the ropes but substitute Pat Spillane's goal – from a flowing counterattack that involved Cian Lally – sparked some hope.
Alan McLoughlin was getting involved on the scoreboard and there were fine two-pointers from Luke Towey and Lee Deignan as Sligo managed to make it a one-point gane, 3-15 to 1-20, with four minutes left.
Leitrim, who only scored four points in the last 23 minutes, were grateful for goalkeeper Killian Gaffey's superb save when he turned over Cian Lally's goal effort as a point resulted instead of the goal that Sligo so desperately needed.
Sligo had the chance to go for a two-pointer from a free with the game's last play but opted not to shoot at goal with a direct kick.
Sligo: Aidan Devaney, Tommy Ross, Conor Sheridan, Luke Casserly, Canice Mulligan, Jack Lavin (0-01), Paul Kilcoyne, Darragh Cummins, Luke Towey (0-03, 1tp), Lee Deignan (0-07, 1tp, 1f), Alan McLoughlin (0-05, 3f, 1tp), Cian Lally (0-01), Joshua Flynn, Niall Murphy (0-02, 1f), Shane Deignan
Subs used: Pat Spillane (1-00) for Joshua Flynn, h-t; Kyle Cawley for Shane Deignan, h-t; Daire O'Boyle for Paul Kilcoyne, 47; Gavin Gorman for Niall Murphy, 49; David Quinn (0-01) for Conor Sheridan, 61
Leitrim: Killian Gaffey, Cillian McGloin, Conor Reynolds, Sean Harkin (0-02), Eoin McLoughlin, Mark Diffley, Keith Keegan, Conor Quinn, Barry McNulty (1-06, 1tp, 1f), Fergal McLoughlin (0-01), Riordan O’Rourke, Tom Prior (0-02), Ryan O’Rourke (1-00), Gavin Reynolds, Oisin McLoughlin (0-03)
Subs used: Ben Guckian for Fergal McLoughlin, 55; Eanna McNamara for Eoin McLoughlin, 55; Paul Honeyman (0-01) for Oisin McLoughlin, 58; Jack Kelly for Tom Prior, 62l; Michael McKiernan for Gavin Reynolds, 62 (temporary)
Referee: Fergal Kelly (Longford)