Tottenham have began their second European campaign at Wembley strongly.
After their struggles in the Champions League and Europa League last season, Spurs took just four minutes to opening the scoring in the new campaign.
Korean winger Son Heung-min scored the opener after running down the left wing. He found his was into the box, but somehow his shot beat Roman Bürki at the near post.
Dortmund's new signing Andriy Yarmolenko equalised minutes later, but Spurs took the lead once more through Harry Kane.
The goal was almost a carbon copy of the opening minutes later as Bürki was once more beaten at the near post.
It's looks like near-post training will be need for the Swiss international when he returns to training in Dortmund.
Spurs maintained their 2-1 lead to half-time.