A disappointing stalemate at Leverkusen leaves Dortmund bottom, while a stunning performance sees Mainz beat Paderborn 5-0.
Borussia Dortmund showed little sign of putting their pre-winter break woes behind them as they sunk to the bottom of the Bundesliga with a 0-0 draw at Bayer Leverkusen on the league's resumption.
Saturday's late game saw both sides create little in the final third, although Leverkusen goalkeeper Bernd Leno was perhaps lucky not to be dismissed just before the quarter-hour mark, after appearing to handle the ball outside the box as he smothered to deny Ciro Immobile.
There were few other talking points at the BayArena, with the result consigning Dortmund to the bottom of the table and piling the pressure onto coach Jurgen Klopp.
Leverkusen's slip-up allowed Borussia Monchengladbach to move back into the driving seat in the race for a UEFA Champions League spot, with Patrick Herrmann's 71st-minute goal handing the visitors a 1-0 win over Stuttgart.
Monchengladbach now sit third, level on points with Schalke, who beat Hannover by the same score despite Klaas-Jan Huntelaar’s dismissal late in the second half.
One of the biggest surprises of the day came at Mainz, as a Yunus Malli brace inspired a 5-0 win at against Paderborn.
The 22-year old opened the scoring after just six minutes with a drilled low finished, before poking home a shot to double his tally two minutes into the second half.
Malli was on hand to create his side's third midway through the second half, teeing up Pablo De Blasis to drill a shot home, before Sami Allagui and Johannes Geis added two more in the space of five minutes late on.
A first win in 10 games leaves Mainz four points clear of the relegation zone and sees them leapfrog Saturday's opponents to sit in 11th place.
Fellow strugglers Freiburg were also in fine goalscoring form, claiming a 4-1 win at home to Eintracht Frankfurt thanks to debutant Nils Petersen's 25-minute hat-trick from the bench.
Hamburg's relegation worries continued after a Marcel Risse brace consigned them to a 2-0 defeat at home to Cologne.