Borussia Dortmund took a step towards the Champions League quarter-finals thanks to a 63rd minute goal from Karim Adeyemi against Chelsea.
The winner came through a blistering counter attack led by Raphael Guerriero who released Adeyemi, who ensured the win with a brilliant run and finish.
Chelsea will have some consolation though in that there is only a one goal deficit when the Bundesliga side travel to Stamford Bridge for the second leg.
However, it is the latest setback for Graham Potter's side who are struggling domestically.
Here, Sportsmail's ADRIAN KAJUMBA takes a look at some of the things you may have missed from the Signal Iduna Park.