St Pat's and Dundalk both picked up important wins as Shamrock Rovers lost to Shelbourne.
Second-placed St Pat's defeated Drogheda United 2-0 at Richmond Park to move within five points of leaders Shamrock Rovers, who suffered a 2-1 defeat away to Shelbourne.
Dundalk continued their strong form with a 1-0 win over Galway United, leaving them just three points behind third-placed Bohemians, who were beaten 4-1 by Derry City at the Brandywell.
At the bottom of the table, Waterford boosted their survival hopes with an impressive 4-0 victory over Sligo Rovers.
Shamrock Rovers remain top on 40 points, followed by St Pat's on 35, Bohemians on 34, and Dundalk on 32.

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