St Loman’s raced into a 0-7 to 0-1 lead by the 17th minute but a goal by Ciaran Curley brought Shamrocks into contention.
Midway through what was a fiery first half both teams were reduced to 14 players when Donal O’Donoghue of Shamrocks and Ciaran Kilmurray of Loman’s were sent off, but Shamrocks still led at the break by 1-6 to 0-7.
However second-half goals by Paddy Joyce and Conor Twomey gave Shamrocks a commanding lead of 3-6 to 0-9 by the 43rd minute.
John Heslin struck an injury-time goal from the penalty spot but it wasn’t enough.
Scorers for Mullingar Shamrocks: C Curley 1-3 (0-3fs), P Joyce, C Twomey 1-0 each, S Daly 0-2 (1f), D Corroon (f), E Moore 0-1 each.
Scorers for St Loman’s Mullingar: J Heslin 1-6 (1-0p, 5fs), E Price, S Flynn 0-2 each.
MULLINGAR SHAMROCKS: R Tyrrell; A Purcell, K Gavin, M Curley; P Joyce, E Moore, D Gavin; D Corroon, D O’Donoghue; K Daly, S Daly, C Twomey; J Ganley, C Curley, L Smyth.
Subs: A Clinton for Smyth (36), S Quinn for S Daly (46), C O’Leary for Ganley (58).
ST LOMAN’S MULLINGAR: J Daly; S Gilmore, P Dowdall, J O’Toole; D Whelan, G Glennon, P Leonard; C Kilmurray, W McGovern; K Reilly, P Sharry, E Price; C Reilly, J Heslin, C Lynam.
Subs: D Rushe for Leonard (29), S Flynn for McGovern (ht), K Lynam for C Reilly (35), J Plunkett for J O’Toole (46), D Windsor for C Lynam (58).
Referee: Shane Farrell.