High School captain Matthew Darcy, darting from halfway, sealed a handsome victory over Section B newcomers St Patrick's with a superb solo try in injury time at Sutton.
Winger Steven Rooney had crossed for two well-taken tries in the first half before Darcy added a penalty goal to make it 13-0 at the break.
To their credit, St Patrick's had much the better of the second period with their inside centre, John Brady, in particular making several surging runs. High School winger Brian Kelly landed a penalty in the closing stages but St Patrick's were rewarded for their fight-back when prop Sean Gallagher crashed over for a try.
High School: O Wardell; B Kelly, S Prunty, G Sheridan, S Rooney; S Duggan, M Darcy (capt); J McDonald, B Hannonn, P Anglim, M Leahy, C Harding, M Olahan, B Kane, D Lee.
St Patrick's: A McCormack; N Connell, J Brady, P Murray, P Culligan; C Murphy (capt), B Forristal; S Gallagher, C Brady, D McAteer, D Gillic, S Byrne, C Dunphy, N Aughey, S Dawson. Replacement: N Cullinane for Gillic (80 mins). Referee: E Farrell (ARLB).