Owen Hargreaves spoke of Kai Havertz's 'courage and composure' after the Chelsea star scored a crucial penalty re-take.
The German international initially hit the post, but was allowed to take the penalty again after a Borussia Dortmund player encroached on the box and cleared the ball.
Havertz put the second attempt in almost the same spot and fired it past the visiting keeper.
'He showed real courage and composure,' said Hargreaves on BT Sport. 'He was brilliant today. He delivers. He showed real composure in big moments.
'This is a huge moment for Chelsea, it could turn everything around for them.