The Germans opened up a 4-0 lead with 30 minutes remaining in Berlin thanks to a Miroslav Klose brace and goals from Mertesacker and Mesut Oezil.

But remarkably, Germany squandered a dominant position against their Group C opponents.

"I really cannot explain what happened here tonight," the Arsenal defender said. "We are all just very disappointed after a game like that.

"But what I can say is: If you are four goals in front and dominate the match then can't just play with half power. That doesn't work on this level.

"Against a team like Sweden every little mistake gets punished and that is lesson we have to learn."

Mertesacker admitted his team-mates have to learn from the experience.

"You know, everything is possible in football, even that I score a goal," he said.

"It's a physical impossibility like the comeback from the Swedish team tonight.

"Maybe some important lessons we just need to learn. It may be the right place in a qualification for big tournament like the world cup but in the end I can't explain this game. We have to give 100 percent all the game."

Former Germany striker Oliver Bierhoff pinpointed complacency as the reason for the team's remarkable collapse.

"I had some experiences as a player myself, but to lead 4-0 at home and to have been so dominant and give the match away, I didn't do that," the Germany team manager said.

"Everybody is doing less because they thought the game was over and they have become complacent. We battled for the ball a lot less and seemed to slow down as well.

"Then we gave chances to the opponent. They got back to 4-2 very quickly and that gave them the momentum. We just haven't been able to put the plug back in and switch our game back on."

Meanwhile, Zlatan Ibrahimovic labelled Sweden's incredible comeback as one of the best moments in his career.

The Paris Saint Germain striker scored himself, while team-mates Mikael Lustig, Johan Elmander and Rasmus Elm wrapped up a famous point, much to the delight of the travelling supporters.

"I do not know if it is possible to explain," Ibrahimovic told Kanal 5.

"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."

"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 do not know how to describe it.

"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."