The chants from the 1,000 England supporters, many of whom had paid ten times above the £35 asking price for tickets, were not the most audible inside a raucous Windsor Park but left the downcast manager and players in no doubt that Eriksson has lost his passionate fan base.
Eriksson insisted he would not resign: instead, he declared, he would ensure England do qualify automatically for Germany with two victories at Old Trafford against Austria and Poland in October.
"It is worrying when you hear that, especially so close to the World Cup," said the captain, David Beckham, the only England player permitted to speak to the press. "They have spent a lot of money to watch us here. We love the way they are, but we are all frustrated. It is hard for the manager and for the players to take but we have to accept it."
Eriksson, electing to keep his words to a minimum in light of the worst defeat of his England career, was in no position to contest the terrace call for his dismissal. Though he said: "That is up to the FA [Football Association]. I am not going to resign, I am going to try to make it right in October by winning the two games and qualifying. It is understandable if you lose against Northern Ireland. It is extremely bad.
"It is the worst result of my England career, yes, because it is a qualification game and we should not lose, not even draw. We should be winning matches like this. I am sorry and disappointed, as the players are. I am sorry for the team, for the three points we lost, sorry for the fans who paid a lot of money to be here and want to see us win.
"The result is very worrying. I thought we played extremely well and how we wanted for 35 minutes, we were patient and controlled the game, created some half chances. Then we lost our patience, lost our spirit and we didn't get it back either at half-time or in the second half. It is still in our own hands and it is up to us in October to get six points."
This was Northern Ireland's first victory over England since Terry Neil scored the winner at Wembley in 1972, and a team ranked 116th in Fifa's world rankings were determined to milk the moment.
"This is a great night for us and we are going to enjoy it. We will have a great celebration and it will continue throughout tomorrow, too," said the victorious Northern Ireland manager, Lawrie Sanchez. "Sven is a good manager and England are a good team, even though they are going to be criticised for this. I know this will make things 10 times worse for Sven. They are going to be in the World Cup next summer, no doubt about it, and they have a very good chance of bringing the trophy home."