First-half goals from Richie Feeney, Barry Moran and Danny Kirby did the trick but it was far from straightforward against a gallant young Clann na nGael side that gave as good as they got for long periods.
Clann, making their first appearance in the provincial club championship for 19 years, absorbed the shock of conceding two goals inside the first four minutes to remain in contention throughout. But despite the best efforts of Cathal Shine, Donal Shine and Ultan Harney, they couldn’t manufacture the goal to get themselves back into the mix.
Despite playing against a strong breeze, Feeney goaled inside the first minute and Moran raised a second green flag three minutes later following another flowing move involving Ray O’Malley, Shane Hopkins and Feeney.
In fairness to Clann, they responded with frees from Jamie Fahy and Donal Shine, but they were hit by another suckerpunch in the 20th minute when Kirby found the net after a quick free from Moran that caught Clann off guard.
But Clann, helped by the introduction of Cathal Callinan and Stephen Flynn, refused to throw in the towel. Cathal Shine landed a free from 50 metres, and two excellent points from play by Harney meant that the Roscommon champions only trailed by four points at the break, 3-3 to 0-8.
The margin was down to just two a few minutes into the second half when a brace of Shine frees hinted at an upset.
However, Castlebar called on their reserves of experience, despite making a plethora of uncharacteristic errors, as Neil Douglas (a free), Paddy Durcan and Hopkins gave the visitors some breathing space.
Clann refused to buckle, and it took a last-ditch block from Tom Cunniffe to deny Harney a certain goal before goalkeeper Rory Byrne snuffed out the rebound.
Castlebar substitutes James Durkan and Cian Costello tagged on scores to confirm their side’s expected progress but Clann na nGael will take great encouragement from a performance that belied the side’s youthful age profile.
D Kirby (1-1); R Feeney, B Moran (1-0 each); E O’Reilly (0-2f); N Douglas (1f), P Durcan, S Hopkins, J Durkan, C Costello (0-1 each).
D Shine (0-9, 8 frees); U Harney (0-2); J Fahy, C Shine (0-1f each).
R Byrne; T Cunniffe, A Feeney, D Newcombe; P Durcan, E O’Reilly, R O’Malley; G McDonagh, B Moran; S Hopkins, N Lydon, A Walsh; N Douglas, R Feeney, D Kirby.
S Conlon for O’Malley (b/s), C Costello for Walsh (36, b/c), J Durkan for Hopkins (45), F Durkan for Lydon (50), S Keane for Douglas (58), R Burke for Kirby (60, b/c)
R O’Reilly; R Gavin, G Pettit, D Flynn; J Connaughton, S Pettit, F Lennon; C Shine, D Shine; E Kenny, J Dunning, M Scally; J Fahy, U Harney, R McManus.
S Flynn for S Pettit (24), C Callinan for Scally (24), D Pettit for Kenny (h-t), D Connaughton for McManus (51), R Naughton for Fahy (51), A O’Reilly for Dunning (60).
J Gilmartin (Sligo).