There were three games in the SSE Airtricity Premier Division tonight, while Shelbourne have been promoted to the Premier Division after six seasons away.
Tonight's 3-1 win away to 10-man Drogheda sees Ian Morris' side crowned First Division champions at United Park.
Drogs had Sean Brennan sent off for picking up two yellow cards just after the hour mark and minutes later Aidan Friel put Shels in front.
However, Luke McNally scored for the home side in the 77th minute to give Shels the jitters as they had to win to get promotion.
Oscar Brennan calmed the Dublin side's nerves again with a goal four minutes later before Lorcan Fitzgerald wrapped things up with a minute of normal time to go. Their 3-1 victory gives them the First Division title and promotion to the Premier Division next year, while Drogheda will have to settle for a place in the play-offs.
Elsewhere in the First Division, Cabinteely secured their playoff spot with a 3-1 win over Athlone, Limerick FC had a 4-1 win over Wexford, while Galway United hammered ten-man Cobh Ramblers 7-1.
In the Premier Division, Dalymount Park saw a 2-1 defeat for Bohemians at the hands of Waterford.
The away side took the lead against the run of play with 12 minutes played as Rory Feely was allowed a free header from a corner.
It took Bohs until the 54th minute to level things as Ross Tierney diverted a Danny Grant shot into the Waterford net.
However, despite the hosts pressing for a winner, it was Waterford who struck for the points courtesy of a stunning shot by Tom Holland into the top corner of James Talbot's net six minutes from time.
At Richmond Park, it finished in a scoreless draw between St Pat's and UCD 0.
The 8pm game at the Showgrounds saw Sligo Rovers beat Finn Harps 3-1 with goals from Niall Watson, Ronan Murray and Sam Warde in a devastating eight-minute spell in the first half. Tony McNamee scored a consolation or Harps in the 88th minute.