Quietly confident of making an impact in this season's Ulster Bank League, Old Belvedere were sufficiently crafty to eke out a victory at Anglesea Road.
A plucky Cork Constitution contributed to an interesting encounter, but Belvedere's cocktail of youth and experience gleaned the spoils.
Having controlled vast chunks of the first half, Belvedere were forced to defend after the restart as Con improved significantly.
Leading by 14 points at the break, Belvedere had assumed a commanding position, but Con trimmed the deficit.
Belvo's advantage had been trimmed to 14-8 as Con threatened a daring escape mission, but the home outfit prevailed. Aidan Wynne drilled a pressure penalty before Danny Riordan's splendid break culminated with a last-gasp penalty try being awarded.
Two first quarter Wynne penalties ensured Belvo, with centres Peter Robb and Rory O'Loughlin prominent, seized the initiative.
Belvo did crash over for a try in the 32nd minute when blindside flanker Jack O'Beirne finished off a fine move. Wynne added a penalty on 37 minutes as Belvo went in to the half-time interval armed with a healthy 14-0 cushion.
Con, though, rallied as a 44th-minute try from No 8 Luke Cahill try gave the visitors a drop of hope.
Cathal O'Flaherty was sin-binned a minute later, but Con continued to battle as a 71st-minute Gerald Hurley penalty narrowed the gap.
With only seconds left, Wynne thumped a penalty from 33 yards and Belvo sealed the deal with the last play. Former Connacht full-back Riordan, the class performer on view, made the dart as a penalty try was then rewarded for a deliberate knock-on.
Scorers - Old Belvedere: J O'Beirne try, penalty try, A Wynne 4 pens, 1 con. Cork Constitution: L Cahill try, G Hurley pen.
Old Belvedere: D Riordan; R Dunne (S McDonald 80), R O'Loughlin (R Kavanagh 80), P Robb, D Mongan, A Wynne, A Sheehan; A Howard (P O'Regan 55), C O'Flynn (K O'Neill 67), D Lavery (A Howard 70), A Trenier, J Kelly, J O'Beirne (J McWilliams-Grey 51), K O'Gorman, J Slattery.
Cork Constitution: M Keyes; G O'Suilleabhain (R Foley 58), N Hodson, N Kenneally, R Jermyn, D Lyons, G Hurley; G Duffy, A O'Driscoll, C Corkery, C O'Flaherty, G Lawlor, J Murphy, J Ryan, L Cahill.
Referee: M Connolly.
Sunday Indo Sport