It was the early pace of Suranga Lakmal, however, that undid the top order of a side playing their first test without England great Cook who left the worldwide arena in September.
The Surrey wicketkeeper was not even in the original touring party, a late call-up as cover for the injured Jonny Bairstow, but ended his first day in global cricket with a deeply assured 87 not out to his name and dreams of a second day century when play resumes.
In England's second innings an assured unbeaten 146 by Keaton Jennings, his first century since a ton on his 2016 debut that has silenced his critics for now at least, allowed Root to declare at 322 for six.
Sri Lanka were chasing a massive 462 and, resuming on 15 without loss, they never threatened to come back into the contest on Thursday with no rain forthcoming to save them after an overnight downpour.
Alec Stewart believes Jonny Bairstow will have to accept that he is England's back-up wicketkeeper and start thinking as a frontline batsman following Ben Foakes' impressive debut in Sri Lanka.
That brought Moeen Ali to the crease for his latest - and possibly last - attempt to paper over the problems at number three.
Moeen Ali grabbed four wickets for England.
Gillum statement stokes intrigue as Florida vote margin tightens
Rick Scott in his re-election bid by 0.22 percentage points, or 17,344 votes out of more than 8.1 million counted so far. A hand recount, a more thorough process than a machine recount, would happen if the race was within 0.25 points.
Leach eventually made the breakthrough when Silva could not connect with a sweep shot and was dismissed leg before wicket for 30.
The match officials' report raised concerns over Dananjaya's action during the first Test in Galle, where the tourists wrapped up a 211-run victory on day four.
England captain Joe Root (three) also had a deja vu moment when Herath dismissed him for the second time in the match.
"When you´re waking up at 6.30 in the morning and reading about your technical deficiencies it´s not human to say it wouldn´t affect you", he added.
"It's very hard to win Test matches overseas now".
The home skipper's own efforts were hampered by a groin injury, providing a further worry for Sri Lanka with the second Test due to start in Kandy on November 14.
England and Sri Lanka took a point apiece from their opening match at the Women's World T20, after heavy rain in St Lucia forced the abandonment of the first match at the Daren Sammy Stadium.