Schalke were unable to recover fourth position in the Bundesliga from Bayer Leverkusen as they suffered a 3-0 defeat to Ingolstadt on Saturday, as the race for the European places heats up.
Leverkusen moved into the Champions League qualifying spots by beating Wolfsburg 3-0 on Friday, and Schalke's slip-up means they will stay outside the top four this weekend.
Ingolstadt went ahead in the the 29th minute when Moritz Hartmann converted from the penalty spot after Dario Lezcano was fouled by Junior Caicara inside the box.
Lukas Hinterseer doubled the advantage in first-half stoppage time, and Lezcano completed the scoring with 25 minutes remaining.
Mainz also remain in the hunt for a Champions League spot after recovering from Caiuby's opener to win 4-2 at home to Augsburg.
Brazilian Caiuby handed the Bavarian side a ninth-minute lead, but Christian Clemens hit back for minutes later and completed his double following a pair of strikes from team-mate Pablo De Blasis.
A phenomenal Franck Ribery overhead kick from 20 yards was enough for Bayern Munich to overcome Eintracht Frankfurt 1-0 at the Allianz Arena.
Their advantage at the summit remains five points, with Borussia Dortmund edging out Werder Bremen 3-2 at Signal Iduna Park - Pierre-Emerick Aubameyang scoring his 23rd top-flight strike this season in an enthralling second half.
Bottom side Hannover suffered a fifth straight defeat as they went down 3-0 at home to Hamburg, while Darmstadt drew their fourth successive match, 2-2 against Stuttgart.