Dortmund are losing 1-0 to SV Darmstadt 98 at half time of their Bundesliga clash this afternoon, thanks to a goal from Marcel Heller.
Henrikh Mkhitaryan was first to threaten in the seventh minute, but his long-range effort went narrowly wide of the left post before Marco Reus shot over the bar four minutes later.
Heller gave Darmstadt the lead in the 17th minute when he met Jerome Gondorf's cross and directed the ball into the bottom-left corner on the counter-attack.
Pierre-Emerick Aubameyang twice had chances to equalise but he could not hit the target from close range, and headed over the bar a minute later.
Julian Weigl then forced Christian Mathenia into a save when his shot from the edge of the area was heading towards the bottom-left corner as Darmstadt held out until the break.