Captain Morgan (113), passing 50 for the fourth successive time, is the architect-in-chief of England’s new-found commitment to all-out attack in one-day international cricket.
It was appropriate therefore that he was the driving force with his 73-ball hundred – in a record third-wicket stand of 198 with Root (106no) – as they made light of a target of 349-7 at Trent Bridge.
England exceeded by 45 runs, and remarkably with six overs and seven wickets to spare, their previous highest total to win batting second – an achievement which takes them from also-rans in this category to near world leaders, with the joint fourth-highest chase of all time. Morgan had his helpers, most significantly perhaps Alex Hales with a wonderful 67 from 38 balls on his home ground, and then Root.
Collectively, in this day-night fixture, they put notable opponents such as Kane Williamson (90), Martin Guptill (53) and Grant Elliott (55no) in the shade.
The prolific Williamson, and brutal late hitting from Elliott and Mitchell Santner, appeared to present England with a major challenge.
Williamson once again combined to great effect with Ross Taylor either side of Guptill and Elliott’s half-centuries.
Brendon McCullum, who chose to bat on a quick pitch under cloud cover, has yet to click at the top of the order in this series – and once again he went short of 50.
England let slip several half-chances, and one more clear-cut. But none was especially costly, McCullum escaping when Jos Buttler could not hold an inside edge off Mark Wood only to go caught-behind anyway in the same bowler’s next over to end an opening stand of 88.
Then after Guptill was put down low at midwicket off Ben Stokes, the normally very safe Root an unlikely culprit, he too was soon gone.
Again, it was the same bowler who got his reward with a slower ball, but Steven Finn was chiefly responsible with a brilliant outfield catch, running 40 yards from mid-on to deep midwicket to hold a skier at full stretch.
That meant another chance for Williamson and Taylor to add to their prolific gains together already in the series, and they duly took their aggregate for the third wicket past 450.
They had just brought up their third successive century stand when Taylor missed a mow across a full ball from Finn and was lbw.
After a paltry 23 for one had come in powerplay, Williamson found mid-on off David Willey, having hit 12 fours and a six off 70 balls. But Elliott’s 45-ball 50, and then Santner’s 44 off 19 balls – including four leg-side sixes in one over by Yorkshire’s Adil Rashid – meant England’s fightback with the ball was short-lived.
Hales made sure it gathered pace again immediately when they batted.
There were seven fours and four sixes in his demonstration of precision hitting against the new ball, and it was a surprise that he should then fall to an ugly shot, aiming to leg, as he had often, but this time edging Matt Henry on to middle-stump.
Even after Jason Roy went to a blistering catch at cover by Williamson also off Henry, after the century opening stand, Morgan and Root had time to pick off the four balls rather than try to make instant boundary opportunities that were not there.
Root still needed a little luck, on nine, when Taylor never sighted a sharp catch at slip off Mitchell McClenaghan.
If Morgan played a single false shot, it was on 66 when he mistimed a pick-up high into the leg-side off Henry, but just safe between two boundary fielders.
By the time he accelerated to three-figures, with his fifth six over long-on off Henry to add to 11 fours, England had reached a position from which it was no longer possible to envisage defeat.
Morgan eventually holed out at long-leg. But there was to be no late stumble, Root completing his century from 94 balls, and so a series already containing more than 2,600 runs will seek a suitably exhilarating conclusion at Chester-le-Street on Saturday.
Morgan said: tty relaxed in the changing room and we’re trying to keep things as raw as possible and concentrate on the process rather than the result and it seems to be working for us at the moment.”