Shamrock Rovers closed the gap on third-placed Derry City after a comfortable 2-0 victory on another dismal night for Limerick fans at the Markets Field.
Limerick, who haven't won at home in the league since early June, are now looking at a relegation battle with their supporters growing increasing frustrated after another poor performance.
Goals in either half from David McAllister and Ronan Finn separated the sides at the Garryowen venue and left Neil McDonald's side three points off the relegation zone.
Limerick's defensive frailties from set-pieces this season was once again exposed when the unmarked McAllister headed home a Brandon Miele corner four minutes from the break.
The Tallaght outfit doubled their advantage when Finn supplied a low finish after being supplied by Gary Shaw on the hour.
Shaw was denied again moments later, while Rodrigo Tosi almost pulled one back against the run of play with a header from a Trevor Clarke free 17 minutes from time.
Sligo Rovers and Bray Wanderers played out a scoreless draw at the Showgrounds. Neither had managed a win in their last six games ahead of last night's tie so a draw was a fairly predictable outcome.
But it leaves 2012 league champions Sligo Rovers facing an uphill battle to survive in the top-flight, with five of their seven remaining games on the road, where they have failed to win all season.
The only real spark came at the end of the first half, as Karl Moore's tackle on John Russell earned him a booking, with Sligo's Rhys McCabe and Bray's Mark Salmon also seeing yellow for the pushing and shoving that ensued.