A first win at Tallaght Stadium since 2021 ensured Sligo Rovers finished the season in seventh place, with Waterford and Galway drawing at the RSC.
Sligo had been stuck in the bottom two for most of the season, but a massive turnaround in form since the mid-season break, with this afternoon's win against Shamrock Rovers ensuring John Russell's side avoided finishing second bottom.
Ollie Denham had Sligo ahead at half-time, with Owen Elding's penalty early in the second half putting Sligo two goals ahead.
Adam Matthews' goal made for a nervy finishing for the visitors, who held out for a win that ensures they play in the Premier Division next season.
Sligo travelled to Tallaght Stadium knowing a draw would be enough to avoid finishing in the play-off spot, regardless of how the game between Waterford and Galway finished.
Were Waterford to lose, Russell's side would also be safe regardless of how the game in Tallaght finished.
Stephen Bradley made wholesale changes to the side that beat Galway on Wednesday night to confirm the league title, with Aaron McEneff, Cian Barrett and John McGovern the only survivors.
Ryan O'Kane should have had the visitors ahead after 13 minutes, but his header from point blank range was straight at Lee Steacy in the Shamrock Rovers goals.
Graham Burke and Aaron McEneff forced Sam Sargeant into action early on as the Hoops shaded possession.
But having lost defender Sean Stewart in the warm-up, matters got worse for Sligo as midfielders James McManus and Seb Quirk were both forced off early with injuries.
Galway went ahead against Waterford after 16 minutes, but the Bit O'Red knew a win would guarantee their safety without having to rely on other results.
That was certainly Russell's plan leading into this tie, but Sligo had not won a game at this venue in four years.
But, they were fighting for their lives and found the net on 37 minutes.
Will Fitzgerald's cross from the right was sent back into the area by O'Kane with the help of a deflection, and centre-back Denham (above) was on hand to nod in from close range.
Waterford equalised against Galway a minute later, but Sligo went into the break knowing that they would finish seventh if results stayed that way.
And they gave themselves a bit of breathing space eight minutes into the half when Elding dispatched a penalty after O'Kane was brought down by Lee Grace.
A Shamrock Rovers response was inevitable, though, and nine minutes later Stephen Bradley's side pulled one back as Adam Matthews' powerful effort from distance flew past Sargeant into the net.
Bradley continued to ring the changes, but Sligo held out for a massive three points that sees Russell's men avoid a play-off spot.
Shamrock Rovers: Lee Steacy, Adam Matthews (Roberto Lopes, 64), Lee Grace, Egor Vssenin; Sean Kavanagh (Dylan Watts, 64), Darragh Nugent, Trevor Clarke, Cian Barrett, Aaron McEneff (Matt Healy, 64); Graham Burke (Danny Grant, 77), John McGovern (Michael Noonan, 86).
Sligo Rovers: Sam Sargeant; Edwin Agbaje (Conor Reynolds, 71), Ollie Denham, Patrick McClean, Kyle McDonagh; Seb Quirk (Daire Patton, 31), James McManus (Ciaron Harkin, 16); Will Fitzgerald, Jad Hakiki, Ryan O'Kane (Cian Kavanagh, 71); Owen Elding.
Referee: Rob Hennessy.
