In doing so, Old Belvedere scuppered St. Mary's hopes of clinching the final semi-final spot in Division 1A which was snatched by Young Munster, who were derby winners over Garryowen.

Old Belvedere will now switch their focus to a semi-final clash with Division 1B table toppers Clontarf in two weeks' time, yet there is plenty to work on as they almost let this Anglesea Road encounter slip from their grasp.

'Belvo's exciting back-three of Daniel Riordan, David Mongan and Eddie Devitt made quite an impression in the first half, scoring a try apiece and leaving St. Mary's with a mountain to climb early in the game.

The home side were first to get off the mark when St. Mary's were adjudged offside at the breakdown and out-half Conal Keane converted the resulting penalty.

In the opening exchanges, ‘Belvo threatened regularly inside their opponents' half and Keane’s finely-judged kick to touch pinned the visitors back.

When St. Mary’s got their chance to shine, they played an expansive game and pushed play out to either wing but the ‘Belvo try-line was well defended.

St. Mary’s were found wanting when Leo Auv’a broke from a scrum, popped the ball inside to in-form full-back Riordan on the left and he dashed along the touchline and broke free of David Campbell's tackle to touch down.

Only two minutes later, out of nothing, winger Mongan found space on the same wing and used his pace to evade the covering tackle and score ‘Belvo’s second try.

The St. Mary’s defence could not get to grips with ‘Belvo’s quick-running rugby and winger Devitt put a further dent in the Saints' play-off ambitions with a third try before the half hour mark.

But Ciaran Potts' side soon hit back. Winger Ronan Doherty collected a clearance kick and gave a looping pass to out-half Ian McKinley who brilliantly sidestepped a defender and touched down to give the visitors a glimmer of hope at 20-7 down.

Into the second half and ‘Belvo made a stuttering start, allowing St. Mary’s the opportunity to close the gap further.

After a bout of pressure on the try-line, scrum half Campbell passed the ball to prop Rob Sweeney who powered over and left an easy conversion for McKinley to make it a six-point game.

St. Mary’s were now playing with renewed confidence and the magnificent McKinley was on hand once again to collect the ball and make a dash for the line for his second try. McKinley’s missed conversion meant that ‘Belvo clung on to a 20-19 advantage.

Simon Keogh’s sin-binning in the 69th minute gave St. Mary’s the chance to push for victory but they were soon reduced to 14 men themselves when Campbell was shown a yellow card.

Player-coach Andy Dunne had the chance to extend ‘Belvo’s lead with a penalty in the 75th minute but his effort went wide.

Nevertheless, ‘Belvo had the final say when ever-ready Auv’a made a scintillating run from inside his own half, storming through Doherty’s tackle and diving over in the corner to give his side a bonus point victory.