Erik Hamren's men looked well beaten when Mesut Ozil scored in the 55th minute, but the Paris Saint-Germain striker scored a goal that sparked a spirited fightback with 30 minutes remaining.
The 31-year-old believes that Sweden surrendered the initiative in the first 45 minutes, and could hardly put their second-half transformation into words.
"I do not know if it is possible to explain. After 4-0 and I don't know how long was left, half an hour, 35 minutes, so there were not many who would have believed how the match ended, but we did it," he told Kanal 5.
"There were 11 other players who came out in the second half, we played in a completely different way. I think we were too cowardly and had too much respect [for Germany] in the first half. But we got out, got the first and we gained more and more confidence. The second, the third and in the end we scored the fourth.
"I cannot describe it. You see the entire bench run towards the players, everyone is extremely happy and the fans were fantastic today. Individually, it's not the biggest thing I have done before, but as a team it's probably one of the best."
Sweden still trail Germany by three points at the top of Group C in the World Cup qualifiers.