10 Dec, 12:23
Ireland's John Lacey will referee his first ever RBS 6 Nations match in February, while Alain Rolland is also included in the Elite Panel in what is his last season.
Replacements used: Darragh Keller for Bradshaw (50 mins), Gavin Dunne for Toal-Lennon (57), Arthur Lyons for Sweeney (66), Colm McMahon for McGrath (73), Rob Glynn for Sexton (73).
Replacements used: Killian Lett for Myron (36 mins), Simon Crawford for Reilly (44), Jonathan Larbey for O'Flynn (60), Des Merrey for Furlong (60), Myron for Lane (71), Sam Cronin for Shanahan (71), Reilly for Cogan (76).
'Tarf enjoyed the majority of the possession in the opening stages, but St. Mary's did have the chance to cancel out this score with a three-point opportunity of their own just four minutes later.
However, even though Steve Toal-Lennon's penalty was positioned in front of the posts, his attempt drifted wide - much to the relief of the 'Tarf defence.
This was certainly a let-off for the Castle Avenue outfit, but they were the dominant side during the opening quarter.
They looked like they had breached the St. Mary's cover after 10 minutes when Timmy McCoy put centre Evan Ryan through to the right of the posts, but referee Paul Haycock instead opted to award a scrum to the hosts.
Hugh Hogan's men started to settle as the first half progressed, but clear-cut chances were proving hard to come by.
Lane did go close to doubling 'Tarf's lead with a penalty from halfway on 27 minutes only to see his kick sail past the posts, and just when they seemed destined to take a slender lead with them into the second half, St. Mary's hit them with a late sucker punch.
Right winger Darragh Fanning broke through on the left following excellent work by scrum half Matthew D'Arcy for the only try of the contest.
Toal-Lennon was on target with the conversion, ensuring that St. Mary's held a 7-3 lead at the interval.
After a difficult season to date and a tough opening 40 minutes of play, St. Mary's would have been delighted to find themselves in the ascendancy.
They did not have to wait long to increase their cushion, as Toal-Lennon was successful with a long range effort just three minutes after the restart.
This was throwing down the gauntlet to the north Dubliners, but it was St. Mary's who were starting to make the hard yards and Toal-Lennon was extremely unfortunate to see another penalty come crashing off the post in the 48th minute.
By the time St. Mary's were next presented with a potential kick at goal, Toal-Lennon had left the field of play.
His replacement Gavin Dunne was a more than able deputy, and he put further daylight between the sides with a 35-metre effort on the hour mark.
This left 'Tarf desperately needing scores moving into the final quarter, but even though their build-up play was effective at times, they were up against a watertight St. Mary's rearguard who were proving exceedingly difficult to break down.
A 71st minute penalty by Dunne had all the appearances of an insurance score, which proved to be the case as St. Mary's held off a late surge by Clontarf for their third victory of the league run.
Referee: Paul Haycock (IRFU)