Crosshaven made a significant breakthrough at Templeville Road on Saturday as they became the first club from Munster to win the All-Ireland Junior Cup.
Crosshaven carved out a 9-3 half-time lead for themselves, with out-half Liam Delaney landing three penalties, and a late, clinching try from winger Darren O'Keeffe settled the issue.
Monivea, who were also bidding to be first-time winners, had a hat-trick of penalties from their number 10 Ger O'Connor, but leaked eight crucial points in the closing three minutes to finish as runners-up.
A penalty from replacement lock Paul Memery edged Crosshaven ahead again at 12-9 and O'Keeffe's try in the final minute made sure that the trophy was destined for Myrtleville Cross.
As expected, there were early nerves shown by these two first-time finalists and the Corkmen seemed to hold the edge up front, with the experienced Merle O'Connell, Rob Barry and Michael Buckley standing out.
Monivea, coached by Connacht's John Muldoon and Keith Matthews, opened the scoring with a seventh minute penalty from O'Connor.
However, successful strikes from Delaney after 15, 26 and 35 minutes put Crosshaven ahead and coaches David Keane and Sean Conway would have been pretty pleased with their side's first half efforts.
However, the sin-binning of flanker Michael Buckley before the break put them under increased pressure and Monivea, who had a late penalty miss from O'Connor, came more and more into the game.
Fergus Farrell and Willie Parker made good impacts off the bench for the Galway outfit and a second penalty goal from O'Connor cut the gap to 9-6 with just over half-an-hour remaining.
O'Connor split the posts again in the 58th minute to drew his side level, and it was now seemingly a question of who wanted it more.
It was Crosshaven who produced a match-winning finish. Parker was sin-binned for putting his hand out and knocking the ball out of scrum half Paul Cogan's grasp.
The resulting penalty, to the left of the posts, was put over by Memery, who took on the place-kicking duties with Delaney off and full-back Cian McGovern down injured.
And a nicely-taken try from O'Keeffe, who raced onto his own chip to score in the right corner, was the icing on the cake for Crosshaven as they celebrated the biggest day in the club's 39-year history.
Speaking afterwards, Memery, the kicker of that late penalty, said: “I play GAA and stuff like that so I like to see myself as a little bit of a kicker.
“Unfortunately Liam (Delaney) went off. But Cian (our full-back) was down injured as well. So I said every dog has its day, popped up and had a shot.
“I kicked a conversion there last week from the touchline against Ballincollig in the cup.
“There's great strength and depth in this community. Crosshaven would be known as a sailing town but soccer clubs are coming up. So is the GAA.
“We're just delighted now the rugby club is on the map in Ireland as well. We're really happy as a club and as a community.”
Referee: Mark Patton (IRFU)