The Dutchman had led the Gelsenkirchen side to their best-ever start to the Bundesliga season, but a 3-1 loss to Freiburg on Saturday has claimed his job
Bayer Leverkusen cemented their grip on second place in the Bundesliga going into the Christmas break with a 3-0 home win over Hamburg on Saturday.
The breakthrough arrived after just 26 minutes. A cross came in from the left, and Gonzalo Castro tapped it into the path of Stefan Kiessling, who slotted it past Rene Adler, who was returning to his former club.
Kiessling was at the heart of the second goal too, ducking past two players and playing it to Andre Schurrle, who rounded his marker and fired it into the bottom corner. The win was complete with 25 minutes to spare, when Bernd Leno sent a long punt forward which Kiessling latched on to, and lifted the ball over Adler.
Due to Bayern Munich's 1-1 draw on Friday, Leverkusen now sit nine points off the top of the table at the halfway point in the season.
FORTUNA DUSSELDORF 2-1 HANNOVER
Hannover wrapped up the calendar year on a disappointing note, crashing to a 2-1 loss to Fortuna Dusseldorf at the Commerzbank Arena.
The deadlock was broken with half-time nearing. Leon Balogun made good ground down the right and swung in a threatening cross, which Dani Schahin met in acrobatic fashion, sending a scissor-kick beyond Ron-Robert Zieler.
Halfway through the first half, the visitors found their equaliser. Manuel Schmiedebach sent a long ball forward and Mame Biram Diouf took it into his path brilliantly before firing home with an excellent finish.
The former Manchester United man's strike looked to be enough for Mirko Slomka's side to grab a draw, but with full-time looming, Ken Ilso grabbed all three points for his side with a 25-yard free kick.
MAINZ 3-1 STUTTGART
Mainz's recent run of good form continued with a 3-1 win over Stuttgart at the Coface Arena.
It was the visitors who took the lead, with Heinz Muller diverting Martin Harnik's header into his own net just after the break. That did little to dampen Thomas Tuchel's side, though, and they were level only seven minutes later. Zdenek Pospech made good ground down the right and pulled it back for Nicolai Muller, who lifted the ball over Sven Ulreich.
Mainz took the lead with 20 minutes to play. Heinz Muller punted the ball up-field, and it evaded everyone but Nicolai Muller, who grabbed his second by knocking it beyond Ulreich and heading it into the empty net.
The points were secure in stoppage time when Elkin Soto smashed ferocious effort home via the underside of the crossbar.
This result sees Mainz climb into the Europa League places. Stuttgart, meanwhile, remain in ninth.
WOLFSBURG 0-2 EINTRACHT FRANKFURT
Eintracht Frankfurt ended the calendar year in the fourth and final Champions League place thanks to a 2-0 win over Wolfsburg.
The visitors came out of the blocks the quicker of the two teams, and were ahead after just 12 minutes. Pirmin Schwegler swung in a free kick from the left, and Alexander Meier was there to beat his marker to the ball and head it in. To make things worse for the hosts, Josue soon picked up a red card just seconds after the opener.
Soon after, it was two. Stefan Aigner collected a long ball on the edge of the box and squared it to Takashi Inui, who beat the offside trap and swept it home from 12 yards.
Frankfurt end the weekend level on points with Borussia Dortmund. Meanwhile, Wolfsburg are 15th, but hold a seven-point advantage over the relegation places.
SCHALKE 1-3 FREIBURG
Schalke's horrendous run of form has culminated in a 3-1 loss to Freiburg at the Veltins Arena which claimed Huub Stevens' job.
Things started brightly for the hosts, who took the lead after 20 minutes. Lewis Holtby latched onto a high ball over the top and selflessly squared it to Jefferson Farfan, who tapped home despite Freiburg's protestations that he was offside.
The visitors soon fought back, and found an equaliser through Jan Rosenthal, who volleyed Daniel Caligiuri's left-wing cross beyond Timo Hildebrand. Things then went from bad to worse for Schalke, who found themselves behind minutes later when Jonathan Schmid beat the offside trap and finished coolly.
Rosenthal added a third on the hour-mark just after the break to kill off Schalke, but there was still late drama to come. First, Rosenthal tainted his day by picking up a second yellow card, before Klaas-Jan Huntelaar compounded the Konigsblauen's misery by getting sent off himself.
The result sees Schalke drop to seventh, some 17 points behind Bayern, while Stevens was dismissed as coach on Sunday.
WERDER BREMEN 1-1 NURNBERG
Nurnberg and Werder Bremen ended the weekend's action by playing out a 1-1 draw at the Weserstadion.
The visitors thought they had taken the lead on 14 minutes when Eljero Elia played the ball through to Aaron Hunt, who slotted it home, only to see his strike ruled out for offside.
The match remained even, and very tight, and looked to be heading for a 0-0 draw, but with 10 minutes to go, Javi Pinola fed Timo Gebhart, who fired the ball past Sebastian Mielitz.
The away fans, thinking they had grabbed all three points, celebrated, but Bremen did not give up. They poured men forward in an effort to score an equaliser, and it finally arrived in fortuitous fashion, with Kevin De Bruyne's shot taking a deflection of Nils Petersen, and bouncing into the net.
Nurnberg appealed for offside, but no decision was forthcoming, and they were forced into a share of the spoils.