Rory Kavanagh was among the scorers as St. Eunan's impressed in the second half to beat Naomh Conaill (0-15 to 1-8) at O'Donnell Park on Sunday.
It means St. Eunan's top Group D and go into the quarter-finals with three wins from three games.
The Letterkenny side were flat in the first half and trailed by four points at the break. But they came good after half time, although Kavanagh said there's plenty of work to do over the coming weeks.
He spoke to the Democrat's Diarmaid Doherty.