Bayer Leverkusen failed to capitalise on Borussia Dortmund's defeat by falling to a 1-0 defeat at Mainz 05 this afternoon.
Mainz started brightly and both Adam Szalai and Andreas Ivanschitz had shots blocked by the Leverkusen defence in the opening five minutes.
Szalai found space in the box in the 12th minute but clipped the bar with his effort, before Gonzalo Castro went up the other end and fired wide.
Chances fell for both sides but Mainz and Leverkusen were both wasteful in a first half that ended goalless.
The deadlock was finally broken in the 61st minute as Ivanschitz stepped up to convert a penalty following a foul from a corner.
Despite Leverkusen coming close with a few chances, they did not do enough and Mainz hung on for the three points.