Two late wickets gave Ireland hope on an otherwise dominant day for Sri Lanka in the first day of the first Test in Galle.
Dimuth Karunaratne and Kusal Mendis both scored centuries as the home side piled on 386 runs for the loss of four wickets.
Their partnership, worth 281 runs, was the highest-ever in a Test at Galle.
It passed the previous record of 267 set by Mohammad Ashraful and Mushfiqur Rahim for Bangladesh in 2013.
Ireland are seeking their first win in Test cricket since securing Test status in 2017.
Karunaratne won the toss and decided to bat first, scoring his 15th Test century and putting on a big second-wicket partnership with Mendis.
However, Ireland would made two crucial breakthroughs at the end of the day as Mendis and then Angelo Mathews fell within three overs of each other.
Mathews only lasted three balls before taking a wild swipe at a delivery from Ben White.
Early Ireland struggles