Old Belvedere opened their All-Ireland League campaign with a gutsy away win, gaining revenge on St. Mary’s College for a defeat in last season’s top flight semi-final.
With Ciaran Potts now in the head coach hot seat, St. Mary's made all the early running at Templeville Road but could not turn their pressure into points.
Old Belvedere were pinned back in their half for much of the opening period, but managed to score from their first two attacks.
Player-coach Andy Dunne kicked a penalty and then winger Kieran Hurrell collected the game's opening try, which Dunne converted.
'Belvo had the wind at their backs and while Dunne had a fascinating out-half duel with Shaun McCarthy of St. Mary's, the visitors were able to maintain their 10-0 lead for half-time.
Phil Werahiko's charges had the match points within their grasp after flanker Richie Leyden broke through for a Dunne-converted try.
St. Mary's were being met by a defensive wall time and again, and a series of knock ons and poor decisions added to their frustration.
In wet conditions, McCarthy opened the hosts' account with a penalty and replacement Ian McKinley added two more as last season's beaten finalists closed the gap to eight points. The Ireland Under-20 international was making his league debut for the club.
But their efforts at breaching the 'Belvo try-line went unrewarded, leaving Dunne and company to celebrate their maiden Division 1A victory.
Referee: Paul Haycock (IRFU)