Nishan Madushka and Kusal Mendis converted centuries into maiden doubles by baton-charging the Ireland bowlers as Sri Lanka sustained control of the second Test here on April 27.
At stumps on day four, Ireland was 54 for the loss of openers James McCollum (10) and Peter Moor (19) and still 159 runs from making Sri Lanka bat again.
McCollum was brilliantly bowled by offspinner Ramesh Mendis and Moor was dismissed when Angelo Mathews held a superb low catch at short extra cover.
Sri Lanka was pushing for a 100th test win and series sweep with the benefit of home advantage and a fifth-day pitch.
Propelled by Madushka's 205 and Mendis' 245, Sri Lanka declared its first innings on 705-3 — a new ground record — immediately after Mathews notched his 15th and fastest century.
The previous highest total at Galle was 638 by Bangladesh in 2013.
Mathews was unbeaten on 100 off 114 balls after hitting four sixes and six boundaries. Dhananjaya de Silva, who replaced an injured Dinesh Chandimal, was 12 not out.
Sri Lanka started the day on 357-1, still 135 runs behind Ireland's first innings total of 492, and batted with complete control and clear intention to bump Ireland out of the match.
The first session saw Mendis reach his ninth Test century, and his second in a row against the Irish.
Mendis and Madushka added 132 runs on the morning of day four and seven runs after lunch before Andy McBrine ended their stand by removing Madushka for 205.
A length ball pitching around leg stump hit Madushka in front. The umpire was unmoved but a video review was decisive. The Madushka-Mendis stand was worth 268 runs and Madushka hit 22 boundaries and one six in his nearly eight-hour vigil.
"I always look to play risk-free cricket. That helps me get the double century," Madushka said.
"I scored 1,000 runs in the last domestic season and also a double century and a century against England Lions early this year to earn this place in the national side. I am happy I got to bat at the top."
The Irish should have had a third wicket soon after but James McCollum dropped Mathews at midwicket off Graham Hume. Mathews, dropped on 1, made the Irish pay a big price.
While Madushka played a composed innings, Mendis batted ruthlessly, hitting 11 sixes, one short of the world record by Pakistan great Wasim Akram against Zimbabwe, and 17 fours.
Mendis surpassed the previous highest number of sixes by a Sri Lankan — Kumar Sangakkara's eight against Bangladesh in 2014 — and was out at long off going for a 12th six.
Matthew Humphreys completed the catch at the second attempt and Mendis was gone for 245.
Mendis stitched 133 runs for the third wicket with Mathews, who was happy to continue piling up quick runs.
Chandimal was batting on 13 when he injured his right shoulder following a hard landing while diving to the crease. He was taken to hospital for an X-ray.
This is the first time four Sri Lanka batters scored centuries in the same innings, and only the third time in test history after India and Pakistan. Beside Madushka, Mendis, and Mathews, skipper Dimuth Karunaratne made 115 on day three.
The Irish bowlers were made to toil on an unresponsive pitch where Graham Hume (1-87), Andy McBrine (1-191), and Curtis Campher (1-101) shared the wickets.
Stand-in Ireland coach Garry Wilson said they believe they can still save the test.
"In the first innings here, and even in Dhaka against Bangladesh, we have shown the application and the skill levels required to bat a longer period of time," Wilson said. "Hopefully, we can bat deep tomorrow."
