Borussia Dortmund's Bundesliga title hopes have been dealt a blow after a 1-0 defeat against Bayer Leverkusen this evening.
Dortmund threatened first as Pierre-Emerick Aubameyang raced to the byline before crossing the ball to Robert Lewandowski, who saw his shot blocked by Bernd Leno.
However, Sami Hyypia's team were soon in front. Gonzalo Castro pounced on a loose ball and released Son Heung-Min, who rounded Roman Weidenfeller and tapped in.
Chances were at a premium after that, although Leno saved from Lewandowski and Jens Hegeler fired over the bar from the edge of the box.
Manuel Friedrich headed wide from a Nuri Sahin cross as Dortmund came out in the second half looking for an equaliser.
However, the visitors were defending well and restricting their opponents to very little in front of goal.
Lewandowski headed over from a Marco Reus free kick as the clock ticked past 70 minutes, but Leverkusen continued to stifle Dortmund's attacking threat.
The only downside for Leverkusen was a late red card for Emir Spahic after the defender had tackled Lewandowski.
Dortmund pushed forward in the final few minutes, but the closest they came was a Lewandowski shot on the turn that Leno saved.
Sokratis Papastathopoulos then got his second yellow card of the match as both sides finished with 10 men.