Keller crossed three minutes into injury-time in yesterday’s final, then slotted a tricky conversion in the blustery conditions to force a replay, which is likely to be held next week.
Keller had earlier kicked Garbally College into a 3-0 lead in the second minute, but Sligo took a surprise lead on 13 minutes when Ryan Feehily sent Daire Byrne over in the corner.
Matthew Cosgrove was unlucky to miss the conversion as Sligo took a 5-3 lead, but he was soon trying to convert his own try three minutes later.
Once again the powerful wind forced Cosgrove’s kick wide, but with a 10-3 lead in the bag, Sligo Grammar were happy to keep Garbally at bay until the break, which was delayed by 10 minutes after Garbally hooker Niall Higgins suffered a bad injury and was stretchered off.
Garbally found it difficult to cope with the loss of Higgins and after first asking Ireland Schools international Conor Kenny to throw into the lineout, they called upon replacement Conor Noone to fill the role.
In difficult kicking conditions, Cosgrove missed two penalties and two drop-goal attempts and with their 45th Connacht senior title on the line, Garbally, the record winners of the competition, cranked up the pressure in the closing stages.
Grammar defended their line superbly throughout but Keller spotted the gap late on to touch down and then added the extras under intense pressure to force the replay.
Scorers for Sligo Grammar: Tries: D Byrne, M Cosgrove.
Scorers for Garbally College: Try: S Keller. Con: S Keller. Pen: S Keller.
GARBALLY COLLEGE: S Tierney; I Fletcher, P Flannery, S Horan, C Dooley (E McCormack 41); S Keller, D Reilly; D O’Hara, N Higgins (C Noone 34), C Kenny; S Holland, P Claffey; C Barrett, D Connolly, J Codyre.
SLIGO GRAMMAR: R Feehily; TJ Ford, D Byrne, M Cosgrove, P Oloyede; P Kilcoyne, P Brittan; N Walker, J Oloyede, D Smith; A McGuinn, J Sexton; J Conway, D Layden, J Bennett.