Four days on from a 3-0 success over Bosnia-Herzegovina - a scoreline which certainly flattered Gareth Southgate's men - England were subjected to another embarrassing defeat against their Euro 2016 conquerors.
Jon Dagur Thorsteinsson's first-half strike was the telling moment in an excruciating watch for the Three Lions faithful, whose side managed a paltry one shot on target despite having 68% of the ball.
Southgate's charges were arguably fortunate not to lose by more on the evening, although the likes of Declan Rice and Anthony Gordon reflected on the positives after the game, hailing the match as a worthwhile experience ahead of Euro 2024.
Some will certainly argue the other way, though, and here, Sports Mole looks at what Southgate may have learned from England's agonising defeat.
Defensive concerns laid bare as John Stones off injured
Already missing Harry Maguire and the exceptional aerial threat that the Manchester United man possesses in both boxes, Southgate's heart would have been in his mouth when John Stones hit the deck in agony a mere 40 seconds into the match.
The Manchester City man was able to carry on despite feeling the full force of an Icelandic body on his ankle, but he was partly responsible for Thorsteinsson's strike, allowing the striker to cut inside far too easily before beating Aaron Ramsdale at his near post.
Neither Ramsdale nor Stones should have the finger solely pointed at them, as Iceland's goal came from a collective calamity on England's side, as the Three Lions allowed Iceland to play their way out from the back without any real pressure.
The midfield pairing of Kobbie Mainoo and Declan Rice were also invisible when Iceland launched one of their many attacks, several of which stemmed from long balls over the top that Southgate's men failed to deal with, and on too many occasions Iceland were given time and space to line up a shot from 20 or so yards.
Southgate stressed that Stones's substitution was mostly precautionary, but with Maguire already sidelined and Lewis Dunk also carrying a knock, clean sheets may be in short supply for England this summer.
Trent Alexander-Arnold has to start at Euro 2024
Enough about England's alarming defensive deficiencies - as easy as it would be to keep that can of worms open - time to address the Three Lions' disjointed attacking tactics, which Iceland comfortably repelled throughout the 90 with all 11 men behind the ball.
While Cole Palmer began on the right with Phil Foden pulling the strings from a central role, the former's natural inclination to drift infield led to an overload in the middle of the park and a lack of genuine wide threat, barring a couple of bright Anthony Gordon moments.
However, that all changed within a few moments of Trent Alexander-Arnold coming on, as the Liverpool man immediately fashioned two chances, including a stunning low cross which was just behind fellow substitute Ivan Toney.
Alexander-Arnold was a straight swap for Kyle Walker in the right-back role rather than occupying the fluid midfield position he did to brilliant effect against Bosnia, but his position change did not impact his creativity, and he also came within inches of levelling the scores in added time with a deflected strike.
Whether he manages to oust Walker from the right-back position or is selected as Rice's partner in the double pivot, Alexander-Arnold is an absolute must for England's starting lineup at Euro 2024.
Was cutting Jack Grealish a mistake?
England's tepid performance against Iceland came one day after Southgate named his final 26-man selection for the European Championships, and one player who would have been watching through gritted teeth at home would have been Jack Grealish.
Southgate argued that other players in his ranks simply had better 2023-24 seasons than the Manchester City man - a fact that is hard to argue against - but some of his squad were supposedly in disbelief at his call.
As England huffed and puffed without success yet and yet again on Friday evening, it begged whether Grealish would have been a useful option off the bench to provide something unique in the Three Lions' ailing attack.
Team tactics were doing no good against the Icelandic, so it may have simply taken one moment of magic to avoid an embarrassing loss, something that Grealish could have conjured up had he been given licence to strut his stuff in attack.
Of course, hypotheticals in hindsight are not worth dwelling on now, but Southgate will be demanding a whole lot more from his creative assets in Germany lest he live to regret his bold decision.