A great giant came to Tara from a foreign land and demanded tribute or a fight with a hundred men from third-century high king Cormac mac Airt. He got three fights and killed three hundred of Cormac’s warriors. Cormac called on Fionn mac Cumhaill and the Fianna. The giant killed a hundred of the Fianna. Fionn asked Goll mac Morna if he would care to take on the giant in exchange for a third part of the spoils and a bonus, and Goll agreed. They fought all day, and when they stopped at nightfall, Fionn came to the giant in the guise of a storyteller and offered to tell him stories with the condition that he would not fall asleep while he was telling. The giant agreed, and Fionn yarned all night. The giant fought Goll again the next day, Fionn kept him awake all night again, and the same the following day and night, so that finally the giant was so tired he lost half his strength, and Goll killed him.
(from the 16th-century Book of Howth, included in my Meath Folk Tales, 2013, The History Press Ireland)