This was always pencilled in as the weekend that one game would ignite this tournament, and so it proved. It was not the packed-house procession in Ahmedabad on Saturday that did it, but rather the champions’ shock decoronation in Delhi. Until recently England were considered the side most likely to end India’s title hopes, but so far the only thing they have ended is Afghanistan’s 14-game, eight-year World Cup losing run.

England’s greatest white-ball side can now add to their list of achievements a starring role in one of the World Cup’s greatest shocks. From first ball – a leg-side wide from Chris Woakes that was missed by Jos Buttler and ran away to the rope – to last they were profoundly outplayed by Afghanistan, who survived the calamitous self-inflicted dismissal of the imperious Rahmanullah Gurbaz to post a total that, while just 12 more than the one India made light of against them here on Wednesday, proved way beyond these opponents, and England eventually fell 69 short.

Related: England humbled by brilliant Afghanistan in historic upset: Cricket World Cup – live reaction

Thanks largely to Gurbaz’s brilliant, 57-ball 80 Afghanistan set England a target of 285, in theory eminently achievable on this high-scoring ground. But it was with the ball that they truly shone, and while spin has proved their great strength their seamers made some of England’s look distinctly third‑rate – though to be fair that had been the one thing at which they themselves genuinely succeeded. Naveen-ul-Haq and Fazal Farooqi did not get the rewards their efforts deserved, many of England’s boundaries against them coming from edges and mis‑hits, but Naveen produced the day’s defining moment with a beautiful delivery that scuttled Buttler’s middle stump.

Of England’s vaunted batting lineup only Harry Brook faced as many as 40 balls, and it was not until he edged Mujeeb Ur Rahman’s delivery into the gloves of Ikram Alikhil in the 35th over, the eighth wicket to fall with 116 still needed, that victory for Afghanistan became inevitable.

How quickly hard-fought reputations are lost. England arrived in India bearing both of the game’s most important white-ball trophies and an aura of only marginal vincibility, but a fortnight later they are just another team, and not a particularly good one at that. The opening defeat against New Zealand could be written off as an underprepared side having an off day against strong opponents, but the dust has now been blown off, the cobwebs cleared, and beneath them the monolith constructed over the past eight years is weathered and fissured.

Their tournament is not yet over, but the task ahead is clear: they must avoid another shock against Sri Lanka and the Netherlands while beating three of South Africa, India, Australia and Pakistan and in the process significantly improving their net run‑rate. At present the prospect looks outlandishly remote.

This victory is a brilliant achievement for a side whose only previous success in the World Cup was against Scotland in 2015. Of all the shocks this tournament has delivered perhaps only Kenya’s victory against West Indies in 1996 stands above it. But amid the ecstasy Afghanistan’s captain, Hashmatullah Shahidi, will be feeling another emotion: relief. Because it was only his extraordinary act of self-sabotage that kept England in the game. Gurbaz, just 21, had been imperious, scoring freely and without emitting the slightest scent of the most distant faraway chance, but it turned out England did not need to dismiss him at all – Hashmatullah would do it for them, and with his very first ball.

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Rahmat Shah had just been stumped for an eight-ball three, with Afghanistan 122 for two. Hashmatullah came in and hit his first ball to David Willey, temporarily on the field in place of Mark Wood, at short cover, and set off for a run. His decision was so misjudged that though Gurbaz reacted instantly and Willey’s throw was not particularly accurate, he was still two yards short when Buttler swung his gloves through the stumps. His departure from the field was the epitome of fury, ripping off his helmet and thrashing his bat against the boundary padding and a nearby chair before stomping to a dressing room whose residents, if they had any sense, were taking cover behind chairs and locking themselves in toilet cubicles.

Even as they did so, England fans were emerging from behind their sofas. What an innings this was for Gurbaz, and what further chaos might he have wrought? It was immaterial in the end, but none of England’s seamers were spared: Woakes, poor again, was heaved over midwicket; Sam Curran, a little worse than that, flayed for three successive boundaries, the last of them pulled, with absolute confidence, right over the head of the fielder at deep square leg; a short ball from Wood was lifted disdainfully over his shoulder for six. Though Ikram added a crucial half-century no other batter on either side matched his fluency, and Afghanistan could easily have been completely derailed by this self‑inflicted blow. It turned out they had a few more still to land.