Sparkling centuries from Root and Jos Buttler were scant consolation for the tournament hosts and favourites as Pakistan turned the form book on its head, snapping a run of 11 consecutive one-day international losses.
However, defeat in the round-robin stage is not a disaster by any means and Root believes England will regroup ahead of Saturday’s trip to Cardiff to tackle Bangladesh.
“The most important thing now for us as a group is not to panic,” said the England Test captain.
“We know what works for us as a formula, and as a team, but other sides are allowed to play well and we’ve got to make sure we learn quickly and bounce back at Cardiff.
“The temptation is to get a little bit tense, but one of our great strengths as a side is sticking to the way we go about things and be as smart as possible.
“The beauty of this format is that I do believe the best four teams over the tournament will qualify for the semi-finals and we’ve got to make sure we play some good cricket in our remaining games.
“One thing this side doesn’t do very often is to make the same mistake twice and I’m sure the guys will make sure it’s a very different performance against Bangladesh.”
Jason Roy and Jofra Archer, meanwhile,have been fined 15 per cent of their match fee for incidents at Trent Bridge.
The International Cricket Council found opener Roy had breached level one of its code of conduct, using an audible obscenity after a misfield during Pakistan’s innings.
Fast bowler Archer was found guilty of dissent towards an umpire’s decision following a wide delivery.
Both players have also had one demerit point added to their records.
Pakistan captain Sarfaraz Ahmed was fined 20 per cent of his fee, and his team-mates 10 per cent, for a minor over rate offence.
Pakistan won by 14 runs after setting England a target of 349.
It was an occasionally fractious encounter, with the umpires warning England captain Eoin Morgan about his side throwing the ball in on the bounce and later issuing the same reminder to Sarfaraz.
England batsman Buttler seemed to take a look at the ball on his walk back to the pavilion after his knock of 103 came to an end.
Morgan said: “There were discussions throughout the whole of the two innings. The umpires came to me mid-innings and seemed to think that we were throwing the ball in on the bounce too much or it was being over-exaggerated.
“They emphasised it would be the same for both. The conversations that were stopping the game were that Pakistan were doing the same thing.
“Jos was just intrigued to see the ball. When the ball is hit against the LED boards it does scuff it up quite a lot so he was just interested to see if the ball was more scuffed up.”
Faf Du Plessis, meanwhile, believes South Africa can still make the World Cup semi-finals, even with talisman paceman Dale Steyn ruled out of the tournament.
South Africa insisted veteran seam bowler Steyn has suffered a new shoulder injury since arriving in the UK, allowing the Proteas to replace him with Beuran Hendricks.
The Proteas – who face India in Southampton today – have already lost to both England and Bangladesh and have never suffered three opening World Cup defeats.
A loss to India would leave them facing a mountain to climb, although captain Du Plessis remains confident.
Asked if Wednesday’s India clash is make or break for the Proteas’ World Cup chances, Du Plessis replied: “Six games is the target, and there’s seven games left – the main thing is getting to the semi-finals.
“It’s purely just our skills that need to be upgraded. If we can deliver our skills then we will be in good positions. But so far we haven’t been there.
“Hopefully it’s a case of us just getting better every game. And if we do, hopefully we’ll start playing better cricket.”
Hoping Steyn’s international career is not at an end, Du Plessis said: “It’s important for us to be strong for Dale.
“It’s been a tough two-and-half years for him, and he would need support right now.
“The team and management will put things in place to look after him.
“He needs love at the moment, he tried really hard to get fit for this campaign.”