A late strike from full-back Brian Gannon gave Drogheda United a 2-1 win over champions Sligo Rovers at Hunky Dorys Park to secure a Europa League spot next season for Mick Cooke's Boynesiders.
With St. Patrick's Athletic losing 2-1 at Derry City, the win also lifts Drogheda up to second place in the table.
Captain Alan McNally powered a header from Philip Hand's cross past Sligo keeper Richard Brush for the lead goal on the half hour.
Sligo hit back to level a minute into the second half when Liam Buchanan finished to the net from Raff Cretaro's cross.
So incensed were Drogheda that Cretaro hadn't been flagged for offside in the build up to the goal striker Declan O'Brien was sent off after receiving a second yellow card for his dissent.
But Drogheda finished with a flourish as Gannon shot home a minute from time to give them victory and European football next season.
Goals from Simon Madden and David McDaid gave Derry a 2-1 win over St. Pat's at the Brandywell in an FAI Cup final rehearsal.
Right-back Madden put Derry in front as early as five minute, lifting the ball over the out-rushing Barry Murphy having run through onto Stewart Greacen's pass.
In-form striker McDaid doubled the lead on 41 minutes - his fourth goal in six league games - when finishing superbly after Barry McNamee worked the opening.
Chris Forrester got a goal back for St. Pat's on 57 minutes, but Derry held out for the win. St. Pat's may yet need a point to rubber-stamp their qualification for Europe in their final league game at home to Cork City next week.
Gary Twigg bid farewell to Tallaght Stadium in style as he scored both goals as Shamrock Rovers beat UCD 2-1. Twigg will leave the club after next week's final game of the season away to Sligo Rovers.
The 28-year-old Scot delighted the home faithful with two goals on 18 and 20 minutes to put Rovers in control. That brought his tally for the season to 20 and should ensure he finishes the topscorer in the league in three of his four seasons.
David McMillan scored a sublime goal to get UCD back into the match on 22 minutes.
Rovers wasted several chances to stretch their lead again before keeper Oscar Jansson made the stop of the night to deprive McMillan an equaliser late on.
Cork City bounced back from last week's defeat at Shelbourne to ease past bottom side Dundalk 3-0 at Turner's Cross.
Midfielder Gearoid Morrissey put Cork ahead on 23 minutes, shooting to the net from the edge of the area.
Vinny Sullivan scored for the second winning running to make it 2-0 five minutes later before Morrissey set up Shane Duggan to seal the win with their third goal four minutes into the second half.
Two goals in three minutes early in the second half sent Bohemians on their way to a 4-1 win over ten man Bray Wanderers at the Carlisle Grounds.
Wanderers had defender Dave Webster sent off on 32 minutes after he received a second yellow card for fouling Keith Buckley.
Bohs midfielder Dave Mulcahy then broke the deadlock on 51 minutes when showing good composure to shoot past keeper Brian Kane. Buckley shot home Andy Mulligan's cross to double Bohs' lead soon after.
Jason Byrne got Bray back into it from a penalty on the hour mark after Kieran Marty Waters had been taken down inside the box by Michael Barker.
But Mulligan restored Bohs' two goal lead nine minutes later after fine approach play involving Keith Ward and Dinny Corcoran. Ryan McEvoy added Bohs' fourh goal two minutes into time added on at the finish.