The country's highest-achieving Leaving Certificate student said his nine A1 grades came as a huge shock.
Killian Donovan picked up his top marks from Dublin's Gonzaga College after a nerve-filled sleepless night.
But the 18-year-old admitted the moment he finally received his results card remained a complete blur.
"I'm ecstatic, it hasn't sunk in yet," he said.
"I expected to do reasonably well when I came in this morning, but I certainly wasn't expecting to get nine A1s."
Killian, who plans to study medicine at the University of Cambridge, managed to juggle revision with a busy schedule as School Captain.
Fresh from three weeks of "InterRailing", the star pupil from Sandyford said good time management was the key to his success.
"I was also involved in scouting activities so it was just separating my time, dividing it up," he added.
"I got by and it worked out for me."
As soon as Killian received his results he called his parents, scientists Lynda and John.