His stay was nearly a short one, but he was reprieved on review, having been given out well caught down the leg side by Ben Foakes.
England had secured a first-innings lead of 139 thanks to a century on debut by Ben Foakes - man of the match - and a formidable spin attack led by Ali and assisted ably by Leach and Adil Rashid restricting Sri Lanka to 203 in reply.
"Our batting was below par and, if you display that kind of batting, you can't stay in the game", Chandimal added.
'We played some really good stuff, ' Root said.
He offered only one chance on 58, when he would have been lbw on review had Sri Lanka not been dissuaded by the sound of bat on ball.
"Credit goes to England, they played some outstanding cricket".
The 25-year-old became just the 20th Englishman in 141 years of Test cricket to score a hundred on debut and only the second keeper after Prior, who made an unbeaten 126 against the West Indies at Lord's in 2007. But him coming into runs is a good sign for us. 'We can go to Kandy with huge amounts of confidence and look to still improve and get better'.
Moeen Ali, centre, celebrates the wicket of Sri Lanka's Dimuth Karunaratne (Eranga Jayawardena/AP).
England's Jack Leach successfully appeals to dismiss Sri Lanka's Kaushal Silva during the fourth day of the first test cricket match between Sri Lanka and England in Galle, Sri Lanka, Friday, Nov. 9, 2018.
Leach eventually made the breakthrough when Silva could not connect with a sweep shot and was dismissed leg before wicket for 30.
Moeen Ali grabbed four wickets for England.
Stokes took out Dhananjaya de Silva (21) with the last ball before lunch to put England in complete control heading into the afternoon session and more steady progress followed.
First ball after tea, Stokes held a very fine catch at slip when Niroshan Dickwella stabbed at Moeen.
Jos Buttler smashed a quick 35 before being caught off Herath while Foakes belted out 37 before falling to spinner Akila Dananjaya.
"We had taken five wickets early but we couldn't take the game forward", Hathurusingha said.
Such an ambition is a long way from being fulfilled but the 211-run victory was Root's first as captain overseas and ends a winless sequence of 14 matches stretching back to October 2016 when England beat Bangladesh in Chittagong.