Dortmund's Hummels relieved after epic comeback

Dortmund left themselves with a mountain to climb at Odds' Skagerrak-Arena as the Norwegians raced into a 3-0 lead after just 22 minutes of Thursday's Europa League qualification play-off.

In Skien, two hours south of Oslo, the hosts looked on course to claim a famous win after goals from Jone Samuelsen, Fredrik Nordkvelle and a direct free-kick from Espen Ruud by the midway point in the first half.

But Dortmund roared back with a Pierre-Emerick Aubameyang brace either side of a Shinji Kagawa strike to make it 3-3 with 15 minutes remaining before Heinrikh Mkhitaryan headed home the 84th minute winner for his seventh goal in four games.

"The end result outweighed the irritation that we didn't score a fifth or sixth goal," said Dortmund's captain Hummels as his side conceded their first goal after just 14 seconds, but hit the crossbar twice in the opening 30 minutes.

"It was a catastrophe of a start -- like something out of a bad film.

"We were lucky in the second-half that we could get it back to 3-3.

"It was good for morale that we fought back, but you should never go into a match with sleepiness like that."

The result means Dortmund have now won all five of their competitive matches under new coach Thomas Tuchel.

His predecessor Jurgen Klopp once described the team as "monsters of mentality" after they fought back from a goal down away to Mainz in 2011 in the Bundesliga and the current Borussia side showed a similar fighting spirit.

Their director of sport Michael Zorc described the opening half an hour in Norway as "a bad nightmare" and Tuchel admitted he was shocked by how badly his defence fell apart early on.

"It was the last thing we wanted. We were unprepared for the start," said the 41-year-old Tuchel.

"I was shocked by how easy it was for them. The Norwegians scored three goals from three chances, then it was a long way back for us.

"In the end, we showed some good morale and could have scored more."

Dortmund are now in a good position for the home leg against Odds next Thursday with the winners going through to the Europa League group stages.

Having thrashed Champions League side Borussia Moenchengladbach 4-0 on the opening weekend of the new Bundesliga season, Dortmund are at newly-promoted Ingolstadt on Sunday.