Miroslav Klose moved closer to becoming Germany’s all-time top goalscorer with a double early on before Per Mertesacker added a third for the hosts before half time.
Once Mesut Ozil made it 4-0 early in the second half, Germany’s 14th consecutive win in qualifying competitions seemed to be in the bank.
However, Zlatan Ibrahimovic and Mikael Lustig got the comeback under way in the 62nd and 64th minutes before Johan Elmander brought them back to within a goal with 14 minutes left to play.
The stage was then set for Rasmus Elm to grab an equaliser in the third minute of stoppage time to earn Sweden a precious draw to leave Low and his team lost for words.
“I cannot explain it so soon after the game has finished,” he said.
“It is hard to explain how we could throw away such an advantage.
“To throw away a 4-0 lead is normally impossible. I am shocked. I have never experienced anything like it.
“Everybody in the dressing room is stunned to silence; we are speechless.”
Low was critical of the way his side let their commanding lead slip in such dramatic fashion, but refused to see only negatives in the performance.
“For 60 minutes, we were sensational and there was no sign of what was to come.
“We are incredibly disappointed.”
Captain Philipp Lahm shared that sentiment on his comeback to the side after missing the 6-1 victory over the Republic of Ireland on Friday.
“When you lead 4-0 then only draw 4-4, then something has gone wrong,” he said. “Something like this should never happen to a top team. Clearly we felt it was done and dusted at 4-0, and that is only normal too, but then we lost concentration, made mistakes, lost our organisation and suddenly Sweden score four goals.”
GERMANY: Neuer, Boateng, Mertesacker, Badstuber, Lahm, Schweinsteiger, Kroos,Muller (Gotze 67), Ozil, Reus (Podolski 87), Klose.
SWEDEN: Isaksson, Lustig, Granqvist, Jonas Olsson, Safari, Holmen (Kacaniklic 46), Wernbloom (Kallstrom 47), Larsson (Sana 80), Ibrahimovic, Elm, Elmander.
Referee: Pedro Proenca (Portugal).