National League: Roddy Collins said that Shelbourne looked dead on their feet during their previous two games.
Riled by that or not, the champions regained their impetus and won with ease in the end with Jason Byrne scoring his second hat-trick against City this season to surely hammer the first nail in their relegation coffin.
A hyper start to the match quickly brought chances at both ends, the surprise being that the bottom-of-the-table club had the ball in their hosts' net twice.
The first, on five minutes, was disallowed for pushing by Alex Nesovic on Jamie Harris, though the finish from Tony O'Connor's cross was superbly executed.
Shels had no such reprieve four minutes later as Dublin stunned them to take the lead.
Again the danger came down the right. Efan Ekoku laid the ball off for O'Connor whose shot was blocked, but only into the path of the unmarked Adam Rundle who shot past Steve Williams.
With plenty of players behind the ball in a 3-5-2 formation, Dublin defended desperately before their goal was inevitably breached on 37 minutes.
Scott Friel was penalised for a foul on Ollie Cahill down the left. Alan Moore's delivery from the free-kick was perfectly flighted and Owen Heary arrived to head the ball home.
Striker Byrne ended the game as a contest within four minutes of the start of the second half with a brace of almost identical goals.
Wes Hoolahan and Heary made them both with defence-splitting attacks down the right. Heary got to the end line on each occasion to pull the ball back for Byrne's close-range finish.
Byrne completed his hat-trick on 75 minutes. Moore's through ball was perfectly weighted for the run of Byrne, who calmly chipped over Barry Ryan.
SHELBOURNE: Williams; Heary, Harris, Rogers, Crawley; Cahill (Cawley, 87 mins), S Byrne (Morgan, 87), Crawford, Hoolahan; Moore (G McCarthy, 87), J Byrne.
DUBLIN CITY: Ryan; Henry, Palmer, Cooper; Friel (C O'Connor, 53 mins), A O'Connor (M O'Neill, 75), Byrne, Rowland, Rundle; Ekoku (G O'Neill, 62), Nesovic.
Referee: H Whoriskey (Meath)
