England took command of the first Test on Wednesday after bowling Sri Lanka out for 203 runs and extending its lead to 177 runs at stumps on the second day of play.
Openers Rory Burns and Keaton Jennings added 38 runs for the first wicket in the second innings to extend England's lead with all 10 wickets intact. Burns, who was hit on the helmet while fielding at forward short leg, was untroubled reaching 11.
England's spin trio of Jack Leach, Moeen Ali and Adil Rashid shared eight wickets between them while seamers James Anderson and Sam Curran picked up a wicket each.
Angelo Mathews' 52 was the only noteworthy contribution during the Sri Lankan innings after the hosts lost four wickets in the morning session. A 75-run stand between Mathews and Dinesh Chandimal steadied the Sri Lankan innings briefly but Rashid made the breakthrough when Chandimal stepped out to the leg-spinner and was stumped by Ben Foakes.
England cleaned up the Sri Lankan tail after tea, though the last pair of Rangana Herath and Suranga Lakmal showed some resistance by adding 28 runs off 30 balls. Herath, playing his last Test match, was given a guard of honour by the England players when he walked out to bat. He was unbeaten on 14.
"Our options were poor and it has got more to do with mindset. There aren't any demons on that wicket and it's not a 200 pitch," Sri Lanka batting coach Tilan Samaraweera said. "There were too many soft dismissals."
Foakes scored his maiden Test hundred after resuming on 87. There were some nervous moments as England lost overnight batsman Jack Leach in the morning with Foakes requiring five runs for the milestone.
Anderson played the last four balls of Dilruwan Perera's over safely and in the next over Foakes reached the milestone with an on-drive off Lakmal. He became the sixth batsman to score a hundred on debut against Sri Lanka.
Foakes, the last man dismissed, hit a 107 that came off 202 deliveries with 10 fours.
Foakes walked in with England in deep trouble at 103/5 on Tuesday and stitched some vital partnerships with the lower middle order and the tail to take England's total to 342. Dilruwan Perera finished with a five-wicket haul while Suranga Lakmal claimed three wickets
"It pretty much went to plan for us," Leach said. "We talked at the start of the day about trying to get as many runs as we could and when we went out to bowl just put as much pressure on as possible. We felt we had a good total on the board.
"A great day for Foakesy ... Last winter he was with the side and didn't play and this winter he wasn't going to be involved. It's a funny game and things can change quickly."
England have never won a Test match in Galle and are in a position to create history.
It's been more than two years since the English won a Test match overseas. Since then, they have played 13 Tests away from home, losing 10 and drawing five.
(With AP Inputs)