Corinthians started and finished with tries from props Jamie Dever and Finlay Bealham, but their efforts were only enough for a losing bonus point as Garryowen prevailed on a 23-18 scoreline at Dooradoyle.
The Light Blues matched the visitors' try count with scores from tighthead prop JP Cooney and centre James McInerney, while out-half Jamie Gavin had a key contribution with the boot – he accumulated 13 points (including three penalties) over the course of a game that ended in a nervy fashion for the hosts.
When referee Dermot Blake blew the final whistle after 46 minutes and 17 seconds of second half play, the relief was palpable and audible with Garryowen hanging on grimly to a five-point lead.
Conan Doyle's charges had built a 23-11 advantage but they failed to kick on when in a commanding position, allowing Corinthians to set up a nail-biting finish for the home side and their supporters.
Garryowen started at a high tempo with plenty of bright and inventive play, however Corinthians carved the fixture's first scoring chance and only a foot in touch denied winger Owen Daly a try.
Garryowen lost the ensuing lineout, nonetheless, and Corinthians loosehead Jamie Dever burrowed over for a close range touchdown with Miah Nikora missing the conversion.
The Light Blues went on to dominate the second quarter, although they did cough up possession too easily at times. Front rower Cooney romped in for a try in the 23rd minute following a good spell of skillful ball retention.
Gavin converted and as the Limerick men continued to make the running coming up to half-time, the young number 10 landed a penalty in injury-time for a 10-5 scoreline.
The Garryowen defence was tested on the resumption and Connacht ace Nikora closed the gap to two points with a successful 42nd minute penalty.
As the hour mark approached, the hosts had pushed on to lead 16-11, Gavin firing over two penalty kicks to one from Nikora.
The game was well and truly within Garryowen's grasp after they constructed a terrific 58th minute try. Great hands by locks Paul McCarroll and Aaron McCloskey and scrum half Neil Cronin released McInerney and the centre burst clear to go over under the posts. Gavin added the extras from close range.
That should have been the final nail in Corinthians' coffin, but the westerners responded with Bealham's late converted try and Garryowen had to scrap all the way to the final whistle. The result moves them up to third in the Division 1B table.
The Light Blues face the first of their three trips north next Saturday, taking on Belfast Harlequins at Deramore Park, while seventh-placed Corinthians host bottom side Shannon.
Referee: Dermot Blake (IRFU)