Grainville deservedly equalised three times in match described as ‘an excellent advert for Secondary Schools football’.
Jonathon Grimshaw collected a pass to fire De La Salle ahead from 14 yards only for Ben Cox to equalise when showing good composure to wriggle free and drill the ball low into the goal.
Daniel Kitchen made two fine saves to keep Grainville at bay and Ethan Boudin assisted making a clearance off a goal-line.
De La Salle responded with Ciaran Cooper showing good anticipation to pick up a loose ball to confidently side-foot his team 2-1 ahead.
Grainville countered again to level when defender Daniel Huelin capitalised from six yards after Fabio Santos had touched a corner kick on.
Both sides worked hard to create openings and the next goal came from distance, Jack Stirling scoring from 30 metres to restore De La Salle’s one-goal advantage.
Grainville pushed hard for a third equaliser and it came after a tidy weaving run by Barry Keith.
He rode three challenges well before taking the ball around the goalkeeper to net from an acute angle.
The game was heading towards extra time when Boudin scored De La Salle’s winner.
He hit the ball towards goal from outside the area and it hit a defender to loop up over the goalkeeper for the final goal.
‘It was a cruel blow,’ said Grainville master Jon Kellett.
‘We contributed to all the goals we conceded and that was disappointing.
Saying that we were excellent as a team.
‘Our work-rate was superb and we never gave up.
We had some good chances but their goalkeeper denied us with some good saves.
‘Tonight’s match was an excellent advert for Secondary Schools’ football.’ De La Salle’s Scott Stevenson said: ‘On the balance of play and chances I thought we deserved to win.
It was a good flowing game of football, both sides kept the ball down and it was good to watch.
‘Goalkeeper Dan Kitchen made a couple of good saves at vital times and full credit to Grainville, three times they showed great character to get back into the game.’ De La Salle: Daniel Kitchen; Aaron Weller, Jon Moserez, Chris Young; Paul Walker, Michael West, Jack Sterling, Kyle Rea, Oliver de Gruchy; Jonathon Grimshaw, Ciaran Cooper.
Subs: Ethan Boudin, Sam Crenan, Kieran Lester.
Grainville: Carlos Mouat; Joe Reaney, Callum O’Connor, Daniel Huelin, Russ Ménard, Nathan Carter; Ben Cox, Barry Keith, Tom Hébert, André Carmo; Fabio Santos.
Sub: Stefan Carroll.
Officials: Paulo Martins (2), Calum Dixon, Jonny Willows.