When Daniel Heuer Fernandes got a toe to Maximilian Beier’s one-on-one effort just seven minutes in, it looked like it might be a long afternoon for Die Rothosen.
But they brushed off that early scare and instead endured a dream first half, with Philip Otele opening the scoring when William Mikelbrencis stole the ball away from Daniel Svensson and slid it across the face of goal for the Nigerian to tap in.
More counter-attacking chances soon came the way of the visitors, as Gregor Kobel did well to keep out Ransford-Yeboah Königsdörffer’s near-post drive, before the Ghanaian was offside while heading in the resulting corner.
Nico Schlotterbeck looped a header against the bar for the home side, and Hamburg took advantage just moments later.
Fabio Vieira’s initial effort from distance was palmed out by Kobel, but the Arsenal loanee took it back to slide a brilliant ball through to the unmarked Albert Sambi Lokonga, who lifted his finish into the near top corner from close range.
The start of a comeback did look to be on the cards for Dortmund at the end of the half when Warmed Omari took down Beier in the area, but Felix Nmecha placed the resulting spot-kick wide of the left post.
The second half brought fresh belief for the hosts, and the introductions of Serhou Guirassy and Fabio Silva reinvigorated their attacking play.
Their pressure built until referee Matthias Jöllenbeck pointed to the spot for a second time after Mikelbrencis stepped on Beier’s toe, and this time Ramy Bensebaini made no mistake in rolling down the middle of the goal from 12 yards.
And the score was suddenly level just five minutes later, as Guirassy had a couple of close-range efforts, the second of which crossed the line before Heuer Fernandes could hook it away.
A thunderous Silva effort showed that Dortmund weren’t done there, and they indeed completed their stunning comeback with six minutes to play.
Yet another penalty was given when Miro Muheim handled it in the area, allowing Bensebaini to score again with a well-placed finish into the bottom right.
Heartbreak for Hamburg, whose four-match unbeaten away run comes to an end, while Dortmund stay nine points from leaders Bayern with seven matches to play.
Flashscore Man of the Match: Ramy Bensebaini (Borussia Dortmund)