Paddy McLaughlin headed in an 86th-minute equaliser to clinch a draw for Institute against Linfield at Drumahoe.
The Belfast side dominated the first half, with Aaron Burns, Stephen Lowry, Kirk Millar, Ivan Sproule and Jimmy Callacher unable to convert chances.
Sproule netted on 27 minutes with a deft finish while Stephen Currie missed a good chance and then smashed against the post with Jonny Tuffey beaten.
Linfield lie third in the Premiership table, with promoted Institute sixth.
Warren Feeney's side laid siege on the home goal in the first half, Burns seeing his shot blocked, Lowry having an effort turned away by Michael Doherty, Sproule unable to connect with a cross and Callacher heading wide.
Sproule made amends when he dashed into the box and dinked the ball wide of the keeper for the opener.
Also before half-time, defender Chris Hegarty had a snapshot saved and Sproule fired a shot across the face of goal.
The hosts battled their way back into the game and that late dramatic header earned them what had seemed like an unlikely point after a one-sided first period.