England v Sri Lanka: Jonny Bairstow's century outstanding - Jonathan Agnew
England are in full control of the first Test against Sri Lanka after a remarkable day in which the game moved on at a remarkable pace.
It was honours pretty much even after day one, which finished with England on 171-5, but the hosts dominated the second day.
Jonny Bairstow and Alex Hales picked up where they left off and, although Hales will be disappointed to have missed out on a maiden Test century, their partnership was vital in taking England to a respectable total of 298.
You always felt matching that was likely to prove a tall order for an inexperienced Sri Lankan batting line-up against England's high-class attack under dark skies, and so it proved as they collapsed to 91 all out.
Having enforced the follow-on, England really have a stranglehold on this game, and despite the gloomy predictions about Saturday's weather, it would be a major surprise if they don't press home their advantage and take a 1-0 lead in this series.
Assured Bairstow can now flourish
Bairstow's 140, his second Test century, was an outstanding innings and a quite remarkable in the context of what has been a low-scoring game.
In conditions where other batsmen have grafted without finding any real rhythm, he played such a wide range of shots so beautifully, timing the ball superbly.
Bairstow's England career took a while to get off the ground - during his first spell in the side, from 2012 to 2014, he didn't score a century and never quite nailed down his place in the team.
But he's been in wonderful form for Yorkshire for a couple of seasons now and he has now started to translate that assurance to the international stage.
It was his stated ambition to make a Test century at his home ground - where his mother Janet works - and to have achieved it can only help his confidence flourish.
Battling Hales enhances opening claims
Bairstow was well supported by opener Alex Hales, who made his highest Test score of 86 before being caught at cover.
We're used to seeing the Nottinghamshire man play with such freedom for England in limited-overs cricket, but this was a very different sort of knock, in which he reined in his natural aggression and battled away in tough conditions.
During the series against South Africa, Hales struggled - he was guilty of getting out to rash strokes early in his innings and not giving himself the best chance to make a significant score.
I was very impressed by the much-improved application he showed here, but he'll be hugely disappointed with the way he got out, skying the ball to deep cover - he'll be kicking himself to play that shot 14 short of his maiden Test hundred.
Overall though, it was still a critical contribution from Hales. England have been looking for an opening partner for Alastair Cook ever since Andrew Strauss retired in 2012.
Hales will always get out playing an expansive stroke occasionally, but if he can learn to get himself in then dominate, he might just be the man.
Anderson and Broad thrive in perfect conditions
Once Sri Lanka went in to bat, conditions were tailor-made for England's brilliant new-ball duo of James Anderson and Stuart Broad, and frankly it would have been a surprise if they hadn't made hay against a very callow Sri Lankan batting line-up.
Anderson and Broad are high-class operators with bags of experience, and with gloomy skies overhead and some very fine catchers in the slip cordon, conditions were loaded in their favour.
Anderson in particular was magnificent, moving the ball at will, and the fact that he passed Kapil Dev as the sixth-highest Test wicket-taker of all time only served to underline his outstanding pedigree.
Sri Lanka have precious little experience of these English conditions, but I'm afraid - Lahiru Thirimanne aside - they didn't help themselves.
It was an absolute no-brainer for England to enforce the follow-on with the light fading - and although bad light denied them the opportunity to make inroads into the Sri Lanka second innings, the fast bowlers will return fresh in the morning, ready for another crack.
Jonathan Agnew was talking to BBC Sport's James Gheerbrant.