Ludden and Alex Lee were sent off for Johnny Glynn’s men as they were forced to endure a torrid second half on all fronts.
Mervue United took the lead after 10 minutes when Ludden fired in a cross and Paul Dannagher climbed highest to power a downward header past Dean Delaney.
Shels made Mervue pay for their waste on 26 minutes when Peter Hynes stroked home a good through-ball from David McGill.
However, the game was level for just 10 minutes as Mervue took the lead again when a superb delivery from a Nicky Curran free kick was met with a fine header from Mike Tierney, glancing the ball past Delaney.
Shels drew level five minutes after the restart when Colin O’Brien released David McAllister and the midfielder coolly slotted past Martin into the bottom corner.
Shelbourne took the lead after 67 minutes. A cross by Colin O’Brien was turned into his own goal by Mixey Harty, on the field just four minutes. Things went from bad to worse for Mervue as another og with 15 minutes left – this time from Dannagher – sealed the points for Shelbourne.
MERVUE: Martin; Curran, Dannagher, O’Rourke, Farrell (Harty, 63); Ludden, Crehan, Hoban, O’Dowd; Connolly (Keane, 78), Tierney (Lee, 55)
SHELS: Delaney; Quigley (Scully, 63), Brennan, Doherty (Crawley, 45), Synnott; McAllister, McGill, M O’Brien, C O’Brien; Doyle, Hynes (Keely, 90).
Referee: Graham Kelly (Cork).