ST. MARY'S COLLEGE 14 GARRYOWEN 16, Templeville Road
Scorers: St. Mary's College: Try: Paul Nash; Pens: Stuart O'Flanagan, Gavin Dunne 2
Garryowen: Try: Paul Neville; Con: Conor Murray; Pens: Conor Murray 3
St. Mary's College, the long-time leaders, suffered their third defeat in four league games and were made to pay for a poor first half display.
They allowed Garryowen seize the initiative, motoring into a 10-0 lead after 20 minutes' play.
Sure-footed scrum half Conor Murray opened the scoring with a crisply-struck penalty and he then converted a try from former captain Paul Neville.
Full-back Stuart O'Flanagan stemmed the tide with a penalty for the home side, only for the Garryowen pack to up the ante again before half-time and a second penalty from Murray made it 16-3 at half-time.
The introduction of Gavin Dunne at full-back and a change of tactics to a more direct style saw the Dubliners close the gap again.
Two Dunne penalties were followed by a late try from flanker Paul Nash, who profited from a blocked down kick.
But Dunne's conversion attempt from the far right was off target and Garryowen stood firm to register their third win of the campaign, with Murray and locks Frank McKenna and Ed Mackey the visitors' stand-out players on the day.