The former Red Bull Salzburg man scored twice as his side drew with the La Liga giants, which meant Dortmund progressed 5-4 on aggregate.
Haaland broke the deadlock on the 35th minute mark after tapping home a cutback pass from Marco Reus from close range and got his second from the penalty spot nine minutes after break to take his tally in the competition to 20 goals.
Speaking to the media after the game, Terzic reflected on his team’s qualification and also hailed Haaland for his heroics.
"It's been turbulent. We are just happy. It feels really cool," Terzic told reporters after the final whistle. "It's not a matter of course for us to get this far. Now to be among the best eight in Europe makes us very happy. Erling Haaland is just outstanding."
Terzic’s counterpart Julen Lopetegui echoed what the German coach said about Haaland and insists his side must be proud of their display.
“It wasn’t just dominance,” the ex-Spain and Real Madrid coach said. “We didn’t allow a team with spectacular players to play, they barely left their half, but they have a lot of individual quality and they showed it, and it wasn’t easy to deal with that.
"Haaland? Yes, he’s one of the best players in the world and he’s punished us. We rowed hard to die on the shore at the end. We wanted to get through, and I think we deserved to. We played a great game.”