And they passed, ultimately, with flying colours, seeing off Kildare champions Sarsfields on a 1-8 to 0-5 scoreline.
"It's a different type of football, isn't it?" mused Paul Curran, half-sodden but happy, after watching his capital trailblazers survive the elements - and a stern examination from the Kildare men.
It certainly wasn't pretty but, when it comes to late November, there are no trophies for style and being pretty effective is all that matters. On that score, a defensively obdurate Ballymun scored far more highly than a scattergun Sarsfields ... and their reward is an AIB Leinster club football final date with Portlaoise. All roads on Sunday week lead to Cusack Park, Mullingar - a venue with happy recent memories for the 'Mun after their quarter-final stroll past the local Shamrocks.
Newbridge yesterday was far less welcoming, largely because the heavens opened shortly before throw-in and never relented - and also because Sarsfields pushed them far closer than the final scoreline suggests.
St Conleth's Park is never the most prepossessing of venues but here even less so, as the rain fell in sheets and semi-darkness descended towards the end of an attritional semi-final.
By the final whistle, Ballymun had prevailed by 1-8 to 0-5. "It wasn't a six-point defeat, but those who know football know that," was the defiant summation of losing boss John Crofton. Even Curran would concede that the winning margin was "a little flattering" to his Ballymun charges.
"It's scrappy stuff, and every point is important," said the Ballymun boss, reflecting on this first-hand reintroduction to real winter football. "The goal gave us a little bit of breathing space, and I think we were sound defensively -- superb. We only conceded five scores, which is very solid."
But it still required a 47th-minute goal to swing the pendulum firmly back in favour of the then-flagging visitors. After 25 minutes of the first half, they led by 0-5 to 0-1 and briefly seemed poised to accelerate over the horizon. For the next 20-odd minutes, however, they failed to score and Sarsfields had rattled over three points of their own to leave the bare minimum between them.
Even the loss of their attacking talisman Alan Smith, to a third-quarter knee injury, had seemingly failed to stifle the comeback.
Then entered Ted Furman with his game-changing goal. A speculative high delivery by Elliott O'Reilly created the frisson of uncertainly in the Sarsfields goalmouth upon which Furman, a 2010 All-Ireland winner with the Dubs, would pounce.
"I was just there at the right time in the right place," said Furman - which, of course, is what predators are born to do. Yet up to then it had been an afternoon of scoreless frustration for a player who had terrorised Mullingar Shamrocks in the previous round.
"The goal came out of nothing really," Crofton maintained, "and ironically Conor Duffy, I thought, cleaned out Furman - I thought he did a great job on him. It was the one time that the ball broke for him, and that's just the luck of the draw ... the gods smile on you, especially in these conditions."
Conditions, mind you, don't fully explain or mitigate the six-point margin shipped by the hosts. They finished with 15 wides, nine alone frittered away in a first half that ended with them 0-5 to 0-2 adrift. Ballymun, with eight wides, weren't exactly frugal but were paragons of economy by comparison.
The winners could also boast six different scorers from play, including their centre-back Karl Connolly and both midfielders. Only one of the 'Sash' brigade - the luckless Smith - troubled the scoreboard from play.
The opposing managers had a different take on this statistical imbalance. Curran suggested that a lot of the Sarsfields wides were either snapshots or misses from outside the scoring zone, concluding: "I think it was a great defensive performance - a great team performance in the end."
Crofton's take? "We chose the wrong day for that to happen, because a lot of (the wides) weren't necessarily under tremendous pressure.
"We've been running up good scores with limited possession. Ironically, today, we got an awful lot of possession and failed in that task.
"But there's great pride in the voyage here," the Sarsfields boss stressed. "We were a bit of a shambles this time last year after our quarter-final defeat in Kildare, so there's great pride in getting this far.
"A bit of disappointment now that there might have been a little opportunity left (behind)."
That disappointment stems from the plentiful possession enjoyed at different stages by wing-back Conor Tiernan, Gary White and impressive rookie Matty Byrne at midfield, and half-forward Caoimghin McDonnell.
But their lack of a killer instinct was fatal. And as if to underline the point, Ballymun iced their semi-final cake with a spectacular hat-trick of points in the dying minutes - a booming '45' from Dean Rock, a precisely curled touchline free from the same player, and finally Davy Byrne from play.
SCORERS - Ballymun Kickhams: D Rock 0-4 (2f, 1 '45'); T Furman 1-0; J McCarthy, K Connolly, K Leahy, Davy Byrne 0-1 each. Sarsfields: A Smith; R Cahill (2f) 0-2 each; P Brennan 0-1f.
BALLYMUN KICKHAMS: S Currie; Enda Dolan, P McMahon, Eoin Dolan; A Hubbard, K Connolly, J Burke; Davy Byrne, J McCarthy; E O'Reilly, K Leahy, J Whelan; T Furman, D Rock, S Forde. Subs: Derek Byrne for Forde (ht), A O'Brien for Derek Byrne (inj 48), S George for O'Reilly (50), J Small for Leahy (57), F Andrews for Furman (61). Booked: Leahy (18), O'Reilly (28), McMahon (44). Wides: 8 (4+4).
SARSFIELDS: P O'Sullivan; S Hurley, S Campbell, C Duffy; D McDonnell, N O'Callaghan, C Tiernan; M Byrne, G White; C McDonnell, R Cahill, D McKenna; P Brennan, A Smith, R Confrey. Subs: C Walsh for Smith (inj 40), D Nea for Brennan (50). Booked: Tiernan (12), Byrne (51). Wides: 15 (9+6).
REF: E Kinsella (Laois). ATT: 1,500 (estimated).
MAN OF THE MATCH: Dean Rock (Ballymun)