A nervous start from both teams saw both packs of forwards trying to dominate each other with neither gaining much of an advantage.
Dalriada gained their first points when left wing Ewan Rodgers polished off a counter-attack.
Paddy Elliott was successful with the conversion to give his team a 7-0 lead.
Larne hit back with a penalty which Jonny Farquhar scored.
Dalriada’s Thomas Hunter scored a try from 40 metres. The conversion was missed but Dalriada had a 12-3 lead.
Thomas scored another in similar fashion just before the break. Peter Elliott added the conversion to give Dalriada a 19-3 lead at the break.
Five minutes after the restart Thomas Hunter completed his hat-trick with a superb effor to score an unconverted try which increased the Dalriada lead to 24-3.
From the kick-off Dalriada produced rugby straight off the training pitch to once again cross the whitewash throughThomas Hunter. Peter Elliott added the two points to put his team 31-3 ahead.
Jacob Fleck then went over for an unconverted try to make it 36-3.
Ewan Rodgers then scored two tries, one of which was converted by Jacob Fleck, to secure the 48-3 victory for the rampant Dalriada School team.
Dalriada will now play Limavady Grammar in the next round.
They edged past Belfast High by 20-16 on Saturday morning.
A frantic start featured Jamie Young scoring before Jim McCartney added the extras for Limavady.
Belfast High captain Simon White slotted home a penalty but Limavady held control at the break by 10-3 thanks to McCartney.
Sam McBride’s second-half scoring featured an unconverted try for Belfast High.
However, McCartney guided over another penalty for 13-8.
White’s penalty reduced it down to 13-11 before a late Limavady surge led to a David Brown try converted by McCartney.
Belfast High’s late push produced a slick Carl Mullett unconverted try.
The draws are as follows for the Danske Bank Ulster Schools’ Cup third round and Danske Bank Ulster Schools’ Trophy quarter-finals:
Rainey Endowed v Regent House
Banbridge Academy/Dromore HS v Enniskillen Royal GS
Limavady GS v Dalriada
Grosvenor GS v Bangor GS
Lurgan College v Ballyclare HS
Portadown College v Belfast Royal Academy
Royal School, Dungannon v Royal School, Armagh
Friends’ School v Coleraine GS
Wellington College, Belfast v Foyle and Londonderry College
Belfast HS v Larne GS
Antrim GS v Strabane Academy
Cambridge House GS v Banbridge Academy / Dromore HS
All ties on Saturday, January 21.