Schalke were punished for poor composure by a ruthlessly efficient Mainz side. Mainz earned their first win at home against the blue and white Bundesliga team for the first time in nearly nine years.
Mainz 2-0 Schalke
(Bell 28', 31')
Schalke started brightly and were it not for Mainz goalkeeper Lorius Karis, they might have taken a fourth-minute lead - a quick-fire double save denied first Klaas-Jan Huntelaar and then Joel Matip from the resulting corner. Jefferson Farfan fired wide and Leroy Sane just couldn't get his shot away in the box after neat play with Eric Maxim Choupo-Moting as Schalke's strong start continued.
Before the half-hour mark, that good start counted for nothing when Stefan Bell stabbed home after a good corner from Johannes Geis. Three minutes later and things got worse for the visitors from Gelsenkirchen. Another smart corner from Geis found Bell, who got the better of Matip to lean in and head past Ralf Fährmann. Moments later, Geis hammered a free kick wide of the far post as Schalke struggled to get over their shock.
That shock stayed until the second half when Jefferson Farfan had a good chance to pull a goal back, but curled wide with his weaker foot after connecting with Sead Kolasinac's low cross. Roberto di Matteo's side continued to huff and puff, and brought on Leon Goretzka and Julian Draxler, but couldn't find that final ball.
Koo clattered the bar after Shinji Okazaki got the better of Fährmann, as Mainz continued to look more like the side scoring. Geis hit the post from a free kick and both Goretzka and Draxler caught the bar with speculative efforts, but Schalke's efficiency in front of goal stayed second best right until the end of the game. Schalke's Europa League qualifying spot is now only four points safe, while Mainz have guaranteed Bundesliga football for another year.