Cockhill Celtic had the tonic of an early lead, but were unable to hold on in their FAI Senior Cup Qualifying Round game against St. Mochta's at Porterstown Road.
Garbhan Friel gave the Ulster Senior League champions a dream start as he scored a second minute penalty.
But the 2020 FAI Intermediate Cup champions drew level through Gareth McCaffrey from the penalty spot on the hour mark.
Nothing could separate the sides at the end of 90 minutes.
The winner arrived in the first period of extra time when Alan Byrne’ powerful header from Alex O’ Hanlon’s corner found the back of the net for the north Dublin side.
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