A furious Eriksson apologised for England’s 4-1 humiliation and insisted his team won’t make the World Cup finals if they repeat the performance.
Eriksson was angry after seeing his team concede three goals in seven second-half minutes in the friendly clash as England conceded four goals for the first time since they lost to Wales in 1980.
"It was the worst 45 minutes that I have had as England coach. It was a disaster all over the place, nothing went right and I’m very upset.
"I apologise to the fans. It seemed like it was a holiday in the second half and I have told the players that they can forget about the World Cup if they play like that again."
The sides had been locked at 0-0 at half-time but Eriksson made four changes at the break bringing on Michael Owen, goalkeeper David James as well as Jamie Carragher and Glen Johnsen, and the Danes took full advantage.
Charlton striker Dennis Rommedahl, former Newcastle and AC Milan hitman Jon Dahl Tomasson, with his 36th international goal, and substitute Michael Gravgaard set Denmark on their way to victory.
Wayne Rooney grabbed a late consolation for England before substitute Soren Larsen added a fourth for the Danes in injury time.
Eriksson now needs to rally his troops ahead of the next World Cup qualifier against Wales in Cardiff on 3 September.
"I told them they have to treat it as a lesson," said the coach.
"I hope they are all angry about it."
"We just didn’t play to our potential," admitted England skipper David Beckham.
"In the first half, our positional play and football was very good but in the second half we just lost our shape and didn’t do what the manager told us to do at half-time."
The defeat gives England plenty to think about ahead of their next World Cup qualifier against Wales in Cardiff on 3 September.