Denmark inflicted England's biggest defeat for 25 years in a 4-1 friendly romp before a delirious Parken Stadium crowd in Copenhagen, on Wednesday.
Substitute Dennis Rommedahl began a three-goal blitz in the space of seven minutes with a simple tap-in on the hour mark, following a rash sortie by substitute goalkeeper David James.
Rommedahl then set up the second for captain Jon Dahl Tomasson in the 63rd minute and substitute Michael Gravgaard was credited with the third in a goalmouth melee following a corner.
Wayne Rooney, England's best player who had a goal disallowed and a penalty appeal turned down in the first half, scored with a consolation strike in the 87th minute.
But there was still time for Soren Larsen to complete the humiliation by prodding home Denmark's fourth goal.
"The second half was a disaster for us," England coach Sven-Goran Eriksson told SkySports.
"For 30 or 40 minutes we didn't do anything right. If we play football like that we can forget the World Cup."
It was Denmark's first home win over England since the two sides first met in 1948 and only their third victory in 17 meetings.
For England, whose coach and players can expect a roasting from the British media on their return home, it was their worst defeat since going down 4-1 to Wales in Wrexham in May 1980.
Both sides were playing before World Cup qualifying resumes next month.
England lacked any of their usual fluency in the first half, with too many passes going astray to get their attacking game in place, though Rooney's skill and aggression was a permanent menace.
They utterly collapsed in the second half as Denmark pounced on every mistake, challenged for every ball and kept the game firmly in the visitors' half.
Eriksson's side were not helped by six second-half substitutions, notably James, after England and Tottenham Hotspur doctors had agreed beforehand that Paul Robinson would only play the first half.
James began the rot by rushing out to challenge Tomasson, who managed to get clear and wriggle past a tough challenge from Ashley Cole to cross the ball for a tap-in.
Rommedahl reciprocated with a reflex header to an attempted England clearance, setting up Tomasson to simply scoop the ball past James from point blank range.
A downward header beat the hapless England keeper four minutes later, before Rooney latched on to a long ball from captain David Beckham and steered a shot past Thomas Sorensen.
It was 19-year-old's 10th goal for England in 24 appearances and heralded a brief revival of Eriksson's attack, which had been led by Jermain Defoe in the first half and Michael Owen in the second.
But the rickety England defending was exposed once again at the very end as their much-vaunted rearguard was caught flat-footed by a defence splitting pass and Larsen poked the ball into the far corner.
The scale of the defeat was an inescapable wake-up call for Eriksson and his men, and a much-needed boost for the Danes as the two sides prepare for 2006 qualifying.
England are two points behind group leaders Poland, who have played a game more, and face a double header away to Wales and Northern Ireland. The Danes are struggling in fourth place in Group Two before games in Turkey and at home to Georgia.