Tourists record the highest Test score of 492 against Sri Lanka.
Ireland recorded their best Test score of 492 when Paul Stirling and Curtis Campher became the third and fourth Irishmen to make hundreds in the game’s longest format, respectively.
Sri Lanka achieved 81 without loss before rain suspended play on day two in Galle, trailing by 411 runs.
Nishan Madushka was unbeaten on 41, while Dimuth Karunaratne was unbeaten on 39.
After skipper Andy Balbirnie made 95 on the first day, Stirling scored 103 and Campher 111.
Lorcan Tucker made an important 80, while Prabath Jayasuriya, the first Test hero, got five wickets for 174 runs.
Asitha and Vishwa Fernando both took two wickets.
Ireland only acquired Test status in 2017 and has lost all five red-ball encounters.
Their previous best Test score was 339, which came against Pakistan in their first match in 2018.
Stirling retired hurt with cramps on day one after reaching 74 in punishingly hot and humid conditions, but returned to the wicket the next morning after Tucker collapsed.
Stirling smashed Asitha Fernando for six over deep point to complete his maiden Test century.
The batter has now reached the century mark in all three variants of the game.
Soon after, Stirling was out for 103 when he hooked a short delivery into the hands of Dhananjaya de Silva on the fine-leg boundary.
Campher was superbly taken at first slip by a diving De Silva, giving Jayasuriya his third wicket of the innings.
The Sri Lankan openers cruised through the last session, despite Ireland’s quicks finding the outside edge of Madushka’s bat with the new ball.
Ireland leads the two-match series 1-0 after losing the first Test by an innings and 280 runs.