Shannon opens the floodgates
The victory margin, however, was rather flattering, for, with nine minutes remaining, Castletown had capped an enthralling second-half recovery, to level the scores at 1-7 to 0-10 through an Anthony Masterson pointed free.
The football was superb as both sides showed their attacking qualities, but it was Horeswood who struck for the crucial goal six minutes from the end after a David Shannon 45-metre free had restored their lead.
PJ Banville lofted a sideline kick into the goal, which keeper Richard Farrell dropped for Shannon to shoot the loose ball to the net.
One minute later it was all over bar the Horeswood celebrations. Banville knifed through the defence on a magnificent run, before laying the ball off to Declan Murphy, who shot high into the roof of the net, leaving no way back for the reigning champions.
Horeswood, despite playing into a first half wind, looked the sharper and hungier side, as they were in control in most sectors -- particularly midfield, where Thomas Howlin and Paddy Murphy were the dominant pair.
The winners' half-back line of Eddie Shiely, Leigh O'Brien and Barry Hearn were superb and managed, for the most part, to shut out the Castletown attack.
After Banville and Brendan Halpin exchanged early points, Horeswood struck for their opening goal from Shiely after just 12 minutes, leaving them leading 1-2 to 0-2.
The sides went on to trade two points apiece, but Horeswood must have felt comfortable leading 1-4 to 0-4 at the interval, though only a fine save from Shane O'Hanlon denied Masterson a goal in the 25th minute.
Castletown stormed into the game on the resumption, with points from George Sunderland, Masterson (two), and James Lannigan -- with Banville managing one in between -- to reduce the deficit.
When the title holders drew level nine minutes from the end, it was set for a dramatic finish, but with the fightback effort taking its toll, it was Horeswood who put in a storming finish to regain the title they last held in 2009.
Castletown finished with 14 players after having full-back Noel Morris dismissed on a straight red six minutes from the end.
SCORERS -- Horeswood: D Shannon 1-4 (2f), PJ Banville 0-4 (2f), D Murphy, E Shiely 1-0 each, N Collins 0-1. Castletown: A Masterson 0-6 (2f, 1 '45'), C Carty (f), J Holmes, G Sunderland, J Lannigan, B Halpin 0-1 each.
Horeswood -- S O'Hanlon; N Murphy, J Hearn, D Larkin; E Shiely, L O'Brien, B Hearn; T Howlin, P Murphy; N Collins, C Deely, Darren Shannon; D Murphy, David Shannon, P J Banville. Subs: D O'Reilly for Darren Shannon (45), M O'Hanlon for P Murphy (48), E Murphy for Larkin (57), S Collins for N Murphy (60).
Castletown -- R Farrell; R Kinsella, N Morris, D Gardiner; C Molloy, C Morris, C Carty; T Sheehy, J Foley; J O'Shaughnessy, J Holmes, G Sunderland; J Lannigan, A Masterson, B Halpin. Subs: J Aherne for Foley (17); D Holmes for Sunderland (56); A Merrigan for Lannigan (59).
Ref -- I Plunkett (Marshalstown)