Goals from Jason Hughes and Rory Gaffney ensured Limerick FC grabbed the Airtricity League Premier Division spoils with a 2-0 win over Shamrock Rovers at Thomond Park.
The defeat severely dents Rovers hopes of reeling in fourth-placed Derry City in the table, leaving them six points behind the Candystripes who, to make matters worse, now have a game in hand on Trevor Croly's side.
An 11th minute opener from Hughes capped a lively Limerick start as Shamrock Rovers failed to deal with Rory Gaffney's lengthy throw-in.
Sean O'Connor did force a 35th minute save from Barry Ryan before the interval, but Limerick were solid in the second period.
Gaffney decorated a crafty and committed display with a sweet 65th minute goal as Limerick closed the deal with the minimum of fuss.
Limerick's intention to play the game deep in Rovers territory was signalled within seconds of the start as the Blues had two efforts inside a minute.
Rory Gaffney's measured header released David O'Leary, who drilled wide, while following that chance Craig Curran smashed a volley over.
Still, the fact that Limerick were busy and bright meant that Rovers were on the back foot and the visitors leaked a preventable 11th minute goal.
Rory Gaffney's mammoth throw was not dealt with by the Hoops defence and Hughes was crafty enough to slam Limerick in front with a crisp finish.
Rovers eventually settled and could have been on terms in the 35th minute when Limerick custodian Barry Ryan made a fine save to thwart a Sean O'Connor free-kick.
In first half stoppage time Ryan had to be alert again to gather a Danny Ledwith shot as Limerick went in ahead at the interval.
Five minutes after the restart Conor McCormack wriggled clear on the right and then located Karl Sheppard, who fired over.
The third quarter was short on incident with Limerick's assistant manager Malky Thomson ordered from the technical area in the 64th minute.
Seconds later Limerick added a second goal courtesy of a delightful strike from Gaffney, who had been willing throughout.
McCormack flashed the ball across the Limerick goal during a Rovers rally, but otherwise Ryan was cool and composed as the Blues held out.
Limerick FC: B Ryan; P Nzuzi, S Oji, S Folan, R Williams; D O'Leary, S Bradley, Jason Hughes (D Rainsford, 90); C Tiofack (A Bossekota, 53), C Curran, Rory Gaffney (C Murphy, 87).
Subs not used: Shane Cusack (GK), Tony Whitehead, Val Feeney, Barry Sheedy.
Shamrock Rovers: B Murphy; C McCormack, D Elebert, J McGuinness, D Ledwith; K Sheppard (B Dennehy, 70), J Chambers, S Rice, S O'Connor; M Quigley (G McCabe, 70); E Zayed (T Stewart, 60).
Subs not used: R Brush (GK), D Foran, P Sullivan, S Robinson.
Referee: Graham Kelly (Cork).