Both sides had come through their respective sections undefeated and there was little to choose between them in a well-contested game in front of a good crowd.
Ryan Armstrong's goal after just five minutes proved the difference at the end.
The experiment of running a 9-a-side league for under 11s this year has proved a major success.
Sixteen clubs throughout the Fermanagh and Western area entered teams.
Coach of the Ballinamallard side, Denzil McDaniel said that it has been a fantastic experience for all the young players.
Said Denzil: "The BKYL deserves great credit for this initiative. It is a superb step up from mini-soccer. In every one of our nine games, I saw good players in the opposing teams with coaches putting in great work in getting them to play good football.
"Our boys were delighted naturally, and they have been terrific to work with, but the real winner was local youth football and I hope all clubs take heart from this and continue to develop their talent," said Denzil.
With Ballinamallard winning Section One and then defeating Dergview in the semi-final, they came up against Ardstraw in the final, who similarly had won their Section and beat Fivemiletown in the semi-final.
Under the experienced refereeing of Pat Chesters, the Tyrone boys started the better with tall centre-forward Jamie Finlay and little winger Cameron Cooke prominent in attack.
But the Mallard back three of Craig Humes, skipper Dean Corrigan and David McDaniel held their line well and Luke Johnston in goal was secure in anything he had to do.
Gradually the Mallards settled bringing dangerman left winger Jack Largo-Elis more into the game and from one move Ryan Armstrong seized his chance and firmly shot to the net.
Mallards just shaded the first half despite the efforts of Ardstraw's Hempton twins, Adam and Dylan and their prospect Lee McCullagh.
After the interval, Mallards central midfield of Josh Largo-Elis and Sam Robb became much more prominent and set up several chances.
Adam McFarland showed good movement up front and might have scored with an effort over the bar. Jack Largo-Elis also had a chance which he normally would have taken but he played it first time and wide. And Ryan Armstrong continued to look threatening. Ballinamallard failed to finish the game off, however, and a late surge by Ardstraw was dangerous.
But second half keeper Jamie Morrow pulled of a great save low down from Jamie Finlay so that when the final whistle sounded it was the Fermanagh side who emerged victorious in the inaugural running of the competition.
BKYL vice-president Rory Lynch presented the cup to winning captain, Dean Corrigan and medals to all the winners and runners-up.
The game was played in a good spirit between the clubs, and Ardstraw official Willie Scott congratulated his opponents. Only four of his side are overage next year, with Cameron Cooke just eight years old.
"This competition is one of the best things the BKYL has ever done," said Willie. "Until now, the youngsters have mini-soccer up until age 13. This competition gets them organised in a good environment and it is just the sort of experience they need.
"The whole occasion was a great credit to everyone," said Willie.