First-half strikes from Jamie Sage and Eddie Barrett helped Salle into a handsome lead but their opponents showed a never say die spirit to snatch a share of the spoils with the last play.
Thomas Ryan, Paul Kearney, and Aiden Kearney all played important roles in their comeback mission before 2004 Munster medallist O’Brien rattled the net to a huge roar from the Tallow faithful.
Tallow played with wind assistance at first but failed to capitalise on that advantage. On a soggy surface, after heavy downpours throughout the afternoon, De La Salle settled sooner.
On eight minutes, Jake Dillon slipped a pass to Eddie Barrett to shoot across Shaun O’Sullivan to the far corner of the net. Jamie Sage added a second on 16 minutes after Stephen Daniels won possession among a ruck of players (2-3 to 0-3).
Salle established superiority in the half back line with Tom Moran making an impression on the right flank.
Tallow posted the next three scores through Thomas Ryan, Paul Kearney, and Robert O’Sullivan, but they missed three frees to move nearer to the favourites. A brace by Adam Farrell brought his first-half tally to four points as Salle departed 2-6 to 0-8 in front.
The leaders stretched seven points away in the third quarter as Brian Phelan converted a free and Barrett drilled over two from midfield.
Thomas Ryan responded with two frees for the Bridesiders but three wides in a row hindered their recovery effort.
De La Salle relaxed on their advantage in the closing minutes and left the door ajar for Tallow. Thomas Ryan, Aiden Kearney, and Paul Kearney narrowed the gap to two with five minutes remaining. A huge free by Brian Phelan seemed to steady Salle before O’Brien’s late, late intervention.
E Barrett 1-2; A Farrell (2fs), B Phelan (4fs) 0-4 each; J Sage 1-0; S Daniels, K Moran 0-1 each.
T Ryan 0-7 (5fs); P O’Brien 1-1, R O’Sullivan (2 65s, 1f), P Kearney 0-3 each, A Kearney 0-1.
J Coady; S Dalton, I Flynn, S McNulty; B Phelan, E Madigan, T Moran; E Barrett, O Keevers; S Daniels, A Farrell, K Moran; J Keane, J Dillon, J Sage.
J Mullane for Keevers (47).
S O’Sullivan; M O’Brien, D O’Brien, K Kearney; A Kearney, J Henley, R O’Sullivan; K Geary, P O’Brien; S Feeney, B McCarthy, E Sheehan; T Ryan, P Kearney, W Henley.
R Beecher for Feeney (47); J Beecher for Bob McCarthy (55); Brian McCarthy for W Henley (57).