Graham Rusk pounced in the fourth minute of added time to rescue a point for UCD at Richmond Park.
Pat's looked to be on their way to three valuable points thanks to
Anto Murphy's goal on 44 minutes.
Danny North and Ian Daly were involved in the build up before Murphy fired past Ger Barron from inside the six-yard box.
A lapse of concentration by Pat's in injury time allowed Darren Meenan put Rusk in to fire past Gary Rogers and complete a remarkable smash-and-grab by the students.