Mick Foley was back for Athy and he lined out at left corner-back on Patrick Mulvihill, with Dessie Dolan being tracked by 17-year-old David Hyland.
Hyland was very good in the first-half but his wily opponent still had an influence and was outstanding in the second-half, along with his cousin James and midfielder Seánie O’Donohue.
O’Donohue and O’Shaughnessy took over at midfield in that second-half, and that had a crucial bearing on proceedings, as did goalkeeper Cathal Mullins’ four brilliant saves, two of which were from one-on-one situations.
“In the last ten minutes… experience, you can’t buy” said Garrycastle manager, Anthony Cunningham.
“You can’t coach it, it just comes. They maybe lost their shape, got a bit ragged in the finish but they’re some coming team, with very young players. What a future Athy have for themselves in Kildare and Leinster.
“I suppose we were fortunate to get the goal but they were fortunate maybe to get their one so it balanced out. We knew it was going to be very tough here; they’re a very fast team. We’re delighted to be in a Leinster final.”
It took Gary Dolan’s 56th minute goal to give Garrycastle some breathing space and it was his brother who was involved again, his shot for a point coming back off the upright. Gary pounced to rifle to the net.
Mullin made a double-save from Liam McGovern in injury time as Athy made a last ditch bit for redemption but it wasn’t to be.
Athy probably had the better of the play in the opening half and Garrycastle would have been pleased to go in at the change of ends, level on 0-4 apiece.
Almost ten minutes had elapsed before McGovern got at the end of a fine three-man move to open the scoring for Athy but Dessie Dolan converted three pointed frees to help keep the Westmeath champions in touch.
Points from Dolan, Tom McHugh, O’Donohue and Mulvihill pushed them three points clear but a goal by James Eaton, after a searing run by 18-year-old substitute Danny O’Keeffe and shot that also hit the upright, ensured that it was all to play for until Gary Dolan’s strike.
Scorers for Garrycastle: D Dolan 0-4(fs); G Dolan 1-0; J Dolan 0-2; S O’Donohue, P Mulvihill, T McHugh, A Daly 0-1 each
Athy: J Eaton 1-3(0-2fs); L McGovern, P Dunne, D Mulhall (f) 0-1 each
ATHY: J Roycroft; D Hyland, J Kinihan, M Foley; R Bell, E Delahunt, E Kennedy; P Dunne, K Feely; T Gibbons, C Reynolds, L McGovern; D Mulhall, K Brophy, J Eaton.
Subs: D O’Keeffe for Gibbons (40); A Kelly for Mulhall (45); D Holligan for Kennedy (58)
GARRYCASTLE: C Mullin; M McCallon, J Gaffey, T McHugh; K Henson, D Harte, E Mulvihill; S O’Donohue, D O’Shaughnessy; R McGowan, D Dolan, J Dolan; G Dolan, P Mulvihill, J Duignan.
Subs: A Daly for P Mulvihill (43); C Cosgrove for Duignan (54); J O’Shaughnessy for McHugh (57); A Browne for McGowan (58); J McAteer for G Dolan (60)
Referee: S Doyle (Wexford).