Replacements used: Michael Kearney for Crawford (27 mins), Peter du Toit for Cronin (44), Bryan Byrne for Culleton (61), Crawford for Ryan (61), Keith Donoghue for Burke Flynn (70), Ryan for Moran (80).
Replacements used: Harry McNulty for Doyle (27 mins), Andrew O'Byrne for Gavin (half-time), Peter O'Shea for Cooney (half-time), Cooney for Brosnan (59).
Garryowen threatened to take an early lead at Castle Avenue, out-half Jamie Gavin almost putting winger Ronan O'Mahony through for a try in the opening minute with an enterprising chip.
The visitors were narrowly denied on this occasion, but they broke the deadlock five minutes later when Gavin landed a 30-metre penalty from a tight angle on the left.
Clontarf were displaying signs of nerves during the early exchanges, and Garryowen sought to take advantage with a number of crunching tackles.
Indeed, the Limerick side looked set to double their lead 13 minutes in when Gavin stepped forward for a seemingly routine penalty just outside the 22-metre line, but the normally dependable number 10 was wide of the mark.
This was a major let-off for the hosts and as the action moved beyond the opening quarter, Clontarf settled into their familiar stride.
Having gone close through pacey winger Michael McGrath 26 minutes in, 'Tarf had an excellent opportunity to restore parity from a close range penalty just shy of the half hour mark.
David Joyce's subsequent effort drifted well past the right hand post this time, but the former Dublin University ace made amends after 33 minutes when he touched down for the first try of the contest following terrific approach play from flanker Karl Moran.
Joyce was unable to tag on the conversion, but he finally found his range three minutes into added time with a superb conversion kick after McGrath had reached over with relative ease on the right wing.
This meant that, in spite of a frustrating opening period, Clontarf took a 12-3 cushion into the second half.
With Andrew O'Byrne introduced during the interval instead of Gavin, Garryowen were doing their level best to force their way back into the reckoning.
However, they were helpless to prevent powerful prop Royce Burke Flynn from breaking through for Clontarf's third try of the day 11 minutes after the restart, converted once again by Joyce.
With confidence now at its maximum level, it was only a matter of time before 'Tarf secured their bonus point, and it eventually arrived 68 minutes in when replacement hooker Bryan Byrne scored a converted pushover effort.
Into the closing stages, Garryowen displayed admirable character as they attempted to secure some sort of consolation from their trip to the capital.
However, with former Clontarf flanker Barry O'Mahony in the sin-bin as a result of dangerous play, the Light Blues were finding it difficult to break down a stern home rearguard.
Indeed, Clontarf were always the more likely of the two teams to bring the scoring to an end, and it was a further try from replacement Michael Kearney that brought the curtain down on a fine afternoon at the office for Andy Wood's men.
Referee: Mark Patton (IRFU)