But he added: "In the last 15 minutes we had big problems. Argentina played very well and came forward with a lot of players.
"But we defended well and played with a big, big heart and that's important in football.
"It was a very important victory for us especially after our
second-half performance against Sweden."
England now need only to avoid defeat against already-eliminated Nigeria on Wednesday to reach the last 16.
Eriksson said: "We have to prepare for the Nigeria match like it was the final because now we have things in our own hands and it would be very sad, very stupid, to let it go.
"Nigeria were unlucky against Argentina and hit the post twice against Sweden so I think it will be difficult for us."
Michael Owen, who won the decisive penalty against Argentina, said that the game was an occasion on which every player performed at their peak.
But he insisted: "There was no revenge, nothing like that. It
was a football match and it was great for the supporters.
"It's a great feeling to beat a team like Argentina, one of
the favourites for the tournament - it was a great night for
"It's always nice to win games against world-class teams
"You can't really have a weak link, every single player has
got to play to their maximum and I thought they did that today.
"The keeper was great, none of the back four had a bad game.
"Sometimes you all gel, you all click and that's what happened today."