With Athlone taking a point as it stands, Treaty will have to wait until next week's fixture with UCD to make sure of their spot in the play-offs but its all about the Reds tonight as they look forward to Premier Division football next season.
It was far from glamourous but Shels got the job done as they so often have this season.
Joyous scenes at Tolka as Shelbourne seal the First Division title and return to the Premier Division at the first attempt. The Shels fans are storming the pitch in a wave of red.
Shels are four minutes of additional time away from the title but Treaty are still very much in the game.
Shels almost make sure of the win as Ryan Brennan creates some space for himself at the edge of the box but his shot flies just over the crossbar.
Treaty not lying down here as Anthony O'Donnell works Clarke but his effort is a weak one.
Poynton makes no mistake from the spot and Shelbourne are just 15 minutes away from the league title and promotion.
Penalty for Shels as Shane Farrell is pulled to the ground inside the box.
Treaty are looking the more dangerous of the sides at the moment, threatening from out wide while Shels are struggling to exert much influence on the the game up front.
Treaty almost break the deadlock through Keane, Ludden flashed in a low cross which was met by the Treaty midfielder but the Limerick side were denied by a fantastic reflex save from Brendan Clarke who had had no saves to make up until that point.
Treaty are clawing their way back into proceedings, soaking up the Shels pressure well and looking dangerous on the break. Marc Ludden flashes a dangerous ball across the face of goal but Shels are able to clear.
Shels still looking sharp in the opening minutes of the half but Treaty seemed to have regrouped and the break and are seem much more composed.
A draw would be good enough for Treaty at the moment as Athlone Town are being held by Cabinteely, although the Dublin side have been reduced to ten men.
Galway United are 1-0 up away to Cobh so as it stands, a draw would not be enough for Shels to secure the title tonight.
Scoreless at the break here as Shelbourne came closer and closer to breaking the deadlock after a poor start. The Reds created a succession of chances towards the end of the half and Treaty will be very relieved to hear the half-time whistle.
Shels knocking on the door as Poynton's cross is deflected just wide by a Treaty player. The ball ends up in the Treaty net from the resulting corner but the referee blows his whistle for a foul.
Fantastic skill from En-Neyah to create a chance for Michael O'Connor. The winger produces a Ronaldinho style flip-flap to beat his man but O'Connor's header is deflected over the bar.
Shels looking dangerous from set-pieces yet again as Aly Gilchrist's header comes back off the post.
Treaty attempting to put an end to the one way traffic Sean McSweeney directs a header over the bar from a dangerous cross from Matt Keane.
The Reds are moving up the gears as Ryan Brennan is the lastest player to threaten but his shot is claimed by Ryan. Shels come straight back up the pitch however, with Kevin O'Connor drawing Ryan into another save from an acute angle.
Shels come close from distance again, this time through Georgie Poynton who's low shot from well outside the box skids just wide.
Shels are beginning to take control of proceedings, stringing intricate moves around the edge of the box.
Shane Farrell almost opens the scoring for Shels with a powerful volley from distance which flies just wide of the post.
Treaty look very vulnerable from a succession of Shels corners which culminate in a goalmouth scramble with Yassine En-Neyah's effort eventually being gathered by a relieved Tadhg Ryan.
The game seems to finally be settling down as both sides get into dangerous positions out wide but still no clear chances being created.
Really poor opening here as both sides severly lacking in quality and composure on the ball so far. There's a lot at stake for everyone involved tonight so nerves may be a factor.
Treaty trying to play long balls over the top early on but the quality of the passes and runs have been lacking so far.
A cagey opening few minutes here with loose passes aplenty from both sides.
Dayle Rooney being honoured with a special jersey before kick off to mark 100 appearances for Shels.
Three changes to the Treaty side from last week's draw with Cork City as Sean McSweeney, Conor Melody and Marc Ludden come into the starting XI. Shels are unchanged from their victory over Cabinteely.
Treaty United will hope to spoil the party however, as they can seal their place in the play-offs with a victory.
First Division action from a wet and windy Tolka Park tonight as Shelbourne try to secure the league title and a return to the Premier Division
Competition: 2021 League of Ireland First Division
Date: 7:45 p.m. Oct. 1, 2021