CLONTARF 30 ST. MARY'S COLLEGE 19, Castle Avenue
Scorers: Clontarf: Tries: Michael Keating 2, Sean O'Brien 2; Cons: Martin Dufficy 2; Pens: Martin Dufficy 2
St Mary's College: Tries: Philip Brophy, Conor Donohue, Darragh Fanning; Cons: Shaun McCarthy 2
Mary's were comprehensively knocked off top spot in the Division One table as Clontarf's teenage winger Michael Keating took his tally to four tries in two games.
The former Belvedere College schoolboy talent, who has electric pace, is already making a name for himself after just two AIB League outings.
Backing himself, he twice burned his man on the outside to roar over for a try in each half as a shellshocked Mary's struggled to cope with his threat and the dynamic play of the Clontarf forwards.
Mary's did make a flying start at Castle Avenue, with winger Philip Brophy touching down in the fifth minute.
Clontarf had the wind at their backs in the opening half and overcame that early setback to put Keating and Leinster flanker Sean O'Brien over for tries.
Out-half Martin Dufficy failed to convert either effort but he did put a 35-metre penalty through the posts to see the hosts turn around with a 13-5 lead.
It turned out that by the hour mark, Mary's had leaked another ten points.
Keating and O'Brien again crossed the line, with Mary's simply not able to live with 'Tarf's pack, in which back rowers Heinrich Stride and Simon Crawford starred.
With time ticking on, 'Tarf's third win of the campaign was safe but Mary's did gain some consolation, if not a losing bonus point, with a late salvo.
They created chances that winger Conor Donohue and full-back Darragh Fanning put away, with player-backs coach Shaun McCarthy converting both.
The damage was done however, with Andy Wood's home side running out deserved winners.