Smith has taken over behind the stumps from his county team-mate Ben Foakes, who is Surrey’s first-choice keeper and arguably the best gloveman in the world.
England have seen Smith’s potential to bat in different gears, particularly attacking when left with the tail and, on the day before his 24th birthday, he hinted at vindicating their decision.
Brook played nicely before flapping at an Alzarri Joseph bouncer, not the first time he has been undone by short bowling, and Stokes registered his fifth successive single-figure score in Tests with a poor shot at a very good delivery from left-arm spinner Gudakesh Motie.
Smith found an even tempo with Root, who was also bowled by the impressive Motie, then after Chris Woakes and Atkinson fell in quick succession to the second new ball, he cut loose.
Favouring the mid-wicket region and keen to use his feet, Smith hit each of Shamar Joseph and Jayden Seales over the leg side for six, the latter an enormous blow on to the roof of the Tavern Stand. From having 30 off his first 47 balls, he took 40 off his next 42.
In all, England added 28 runs for the final two wickets, though only Smith scored any runs off the bat until he was well held at deep square leg by Kirk McKenzie to give Seales his fourth wicket.