Extra time needed before Blackrock secure Senior Cup victory.

The 91st Leinster Senior Schools Cup Fina between lBlackrock College and St Mary's College finished level at 12 points each at the end of normal time. Having played 70 minutes the two sides now faced an additional 15 minutes extra time. Six minutes into extra time Blackrock got a try from fullback Patrick Hinkson. Hugo MacNeill kicked the sideline conversion. Two further MacNeill penalties in the second half of extra time sealed victory for Blackrock.

Among the futures Irish senior internationals playing were Hugo MacNeill and Paul Dean.

The 1977 Leinster Senior Schools Cup Final was played on Sunday 20 March 1977 and not the normal St Patrick's Day. This decision was made to protect the Lansdowne Road pitch following poor weather prior to the Ireland v France Five Nations fixture on the 19 March. 

The edition of Sports Club was broadcast 31 March 1977. The commentator is Fred Cogley.