"I`m not going to resign," the England manager insisted. "I`m going to try to make it right, to look forward and try to win the last two games."
Although finishing as runners-up in the group gives England a chance of qualifying for the World Cup, either as one of the two best second-place teams, or through the play-offs, they must beat both Austria and table-toppers Poland to be sure of reaching Germany next summer.
That, though, looked a distant prospect after Wednesday`s shambolic display against a team rated over 100 places below them in the world rankings.
"It`s my worst experience as England manager," Eriksson admitted. "Against Northern Ireland we should not even draw, we should win.
"Of course I am very sorry and disappointed. The players are sorry for the team, sorry for the three points and sorry for the fans who have paid money and want to see us playing better football and winning.
"We played exactly as we wanted to play for 35 minutes. We showed patience and created half-chances. But we lost patience and lost spirit. We didn`t find it at half-time or in the second half and that`s why we lost the game."
The 4-3-3 cum 4-5-1 formation that Eriksson had first tried in the uninspiring 1-0 victory over Wales on Saturday again looked cumbersome.
The deployment of the midfield when he finally switched to 4-4-2 in the second half – with David Beckham retained in the centre, forcing Steven Gerrard into an unfamiliar position on the left with Joe Cole on the right – was frankly bizarre. He maintained, though, that the formation was not to blame.
"I don`t think the organisation or the formation – 4-4-2, 4-3-3 or 4-5-1 whatever – was the problem. Almost all of the players played in the same position they do for their clubs. That can`t be the reason."
Was he, then, concerned that players were not following his instructions? "No," he said. "Absolutely not."
Not only will Eriksson have to lift his side – already shaken by the 4-1 defeat in Denmark last month – ahead of those final two qualifiers, but the first of those games will have to be won without Wayne Rooney, who is suspended having been booked for an elbow on Keith Gillespie four minutes before half-time.
With the red mist well and truly descended, he then led with his arm in a challenge with the full-back Chris Baird and could easily have been sent off. Eriksson admitted he was so concerned that he contemplated replacing him at half-time.
"It`s always a pity to take off such an important player," he said. "You know he can win game for you. He`s young, and I hope he learns."
In contrast with Eriksson`s moroseness, Lawrie Sanchez, the Northern Ireland manager, was positively evangelical.
"Belief," said Sanchez, who knows all about that as he was the goal scoring hero when Wimbledon or the `Crazy Gang` upset the form book and beat Liverpool in the 1988 FA Cup final.
"It`s amazing what you can do if you believe in yourselves. I was brought in 18 months ago to create shocks. I promised on my CV that I can create shocks and this one`s up there.
"I`m the manager but the players deserve credit. The staff and I can only give direction and a game plan. The players have achieved immortality in Northern Irish folklore."
Only a week ago, Sanchez expelled Jeff Whitley and Phil Mulryne from his squad for breaking a curfew, but that seems only to have galvanised spirit within the squad.
As evidence of that Sanchez revealed that the Rotherham defender Colin Murdock insisted on meeting with the squad on Wednesday night, despite the death of his father on Tuesday.
"You live for these moments," he said.
"A week ago we had disruption, but then we had a player come to support the lads on the blackest day of his life. You`re not going to get anywhere without commitment, and if the players aren`t committed you`ve got to lose them."
He also had consoling words for Eriksson, pointing out that reputations aren`t won and lost in one game.
"England are a magnificent team," he said. "They will qualify for the World Cup, and they will be one of the teams who can bring the trophy home.
"This is a hiccup for them, but a magnificent performance from us. We stopped them playing. There were ifs and buts, but in the end we had as many chances as them."
It was only Northern Ireland`s seventh victory over England in 98 meetings, their first since 1972 and almost certainly the most surprising.
Eriksson had gone without defeat in 21 previous qualifiers, but England now trail the group leaders Poland by five points, and, although they have a game in hand they must win their two remaining qualifiers against Austria and Poland next month if they are to guarantee World Cup qualification as group six winners.
Northern Ireland`s dreams of qualification ended long ago, but that hardly mattered at a jubilant Windsor Park.
David Healy`s 74th-minute winner was the first goal Northern Ireland had scored against England in Belfast since Vic Moreland`s effort in a 5-1 defeat in 1979, and it was richly deserved.
David Beckham described the defeat as the worst of his England career.
"Strong words have been said by the manager and the lads have to take it," the England skipper said.
"It has been an embarrassment, but we stick together, that`s what the team is about, even when we`re criticised.
"Tonight hurts more than anything, but we stick together and we have to put it right. If we win the next two games we go top of the group."