Champions Shamrock Rovers took full advantage of dropped points by their rivals after a comfortable 4-0 over UCD at Tallaght Stadium.
An own goal from Harvey O'Brien, and further goals from Jack Byrne and Graham Burke gave Stephen Bradley's side a 3-0 lead at the break in a first half they dominated.
Substitute Kieran Cruise gave them their fourth goal in the 56th minute as UCD's problems continue as they sit bottom of the table.
Derry City dropped points in the title race as they drew 0-0 against Bohemians at the Ryan McBride Brandywell stadium. The hosts had the better chances, and were also denied a late penalty.
The draw leaves them six points behind Shamrock Rovers, with Bohemians two points behind them in fourth.
A late winner from Darragh Markey gave Drogheda a 2-1 win over St Patrick's Athletic, who missed the chance to go into second place.
Adam Foley gave Drogheda the lead in thew 18th minute, before Chris Forrester equalised just before half-time. It looked to be heading for a draw, before Markey's winner in the 94th minute.
A late winner gave Dundalk a 2-1 over Cork City at Turner's Cross to move them closer to the European places. Ruairí Keating's goal in the 20th minute gave Cork City the lead, but Ryan O'Kane drew Dundalk level just before half-time.
John Martin was the match winner with five minutes remaining to claim an important win for Dundalk.
In Tolka Park, it finished 1-1 between Shelbourne and Sligo Rovers. Matthew Smith gave Damien Duff's side the lead after four minutes, before Niall Morahan's powerful strike levelled the game in the 34th minute.
