It was Mainz that ruined Dortmund's hopes of the title last season, and Edin Terzic was again left wondering how his side hadn't managed to come away with a win here.

Julian Brandt scored the Dortmund goal with a superb free-kick, but Jamie Bynoe-Gittens might have had the hosts ahead in the eighth minute had his effort not struck the crossbar.

Marcel Sabitzer also hit the woodwork and then Mainz grabbed an equaliser just before the break when Sepp van den Berg put his header into the net, despite Gregor Kobel's desperate attempt to claw it out at the post.

Mainz did dominate for much of the second half, however Gio Reyna thought he'd stolen the points in the stoppage-time, only for his effort to be ruled out for offside, leaving both sides with a point.

Dortmund might feel lucky sixth-placed Hoffenheim also only took one point from its match against Darmstadt, which ended in a  thrilling 3-3 draw.

That result keeps Dortmund three points clear in fifth, but it is now 12 points adrift of the summit having played a match more than leader Bayer Leverkusen, and two more than second-placed defending champion Bayern Munich.