Werder Bremen's Fin Bartels (R) and Borussia Dortmund's Sebatian Kehl (C) fight for the ball during their German Bundesliga first division soccer match in Bremen, December 20, 2014 (Photo: Reuters)
Borussia Dortmund's Bundesliga crisis deepened on Saturday after suffering their tenth defeat of the season in losing 2-1 at fellow strugglers Werder Bremen to drop to second from bottom.
Having started December at the foot of the table, Dortmund can finish 2014 back at the bottom if Freiburg get at least a point against Hanover 96 on Sunday.
Dortmund continue to have the most defeats in Germany's top flight at the season's halfway stage with just 15 points from 17 games as Bremen picked up the three points to allow them to climb off the foot of the table.
Bremen deservedly claimed only their fourth win of the season.
Jurgen Klopp's Borussia, who will face Juventus in the last 16 of the Champions League, fell behind with just three minutes gone when Bremen's 19-year-old striker Davie Selke curled in a superb goal from 15 metres out.
Selke then turned provider by outsprinting Dortmund captain Mats Hummels to put in a great cross which Bremen midfielder Fin Bartels converted on 62 minutes.
Hummels pulled a goal back when he headed home unmarked a corner from fellow Germany international Ilkay Gundogan on 69 minutes, but it was no more than a consolation.
Second-placed Wolfsburg host mid-table Cologne later on Saturday hoping for the three points which would trim Bayern Munich's huge lead at the top of the table back to 11 points.
Bayer Leverkusen stay third after coming from behind for a 1-1 draw at home to Eintracht Frankfurt.
Eintracht captain Alexander Meier converted a penalty to make him the league's top scorer with 13 goals in 16 games before Leverkusen's Germany winger Karim Bellarabi equalised seven minutes from time.
Roberto di Matteo's Schalke 04, who have drawn Real Madrid in the last 16 of the Champions League, stay fifth in the table after being held to a goalless draw at home to Hamburg in a poor display.
There was some good news for Royal Blues fans before kick-off as Netherlands striker Klaas-Jan Huntelaar extended his contract until 2017 having scored 66 goals in 116 Bundesliga matches.
Stuttgart remain above the bottom three places after their goalless draw at home to Paderborn.
Augsburg fought back for a 2-1 win at home to Borussia Moenchengladbach, who took the lead after only two minutes when Max Kruse converted a penalty before midfielder Markus Feulner and striker Raul Bobadilla scored either side of half-time.
The result leaves Augsburg sixth while Gladbach drop to fourth.
On Friday, Pep Guardiola's Bayern broke more league records as Bastian Schweinsteiger and Arjen Robben scored in their 2-1 comeback win at Mainz after Colombia midfielder Elkin Soto had given the hosts' a shock first-half lead.
The Mainz result saw Bayern claim a new record for the fewest goals conceded in the first-half of the season as their defence have leaked just four goals.
At the season's halfway stage, Bayern will finish the weekend at least 11 points ahead, claiming a new record for the league's biggest advantage at the halfway stage, beating their own joint best mark of 10.
Bayern have also equalled their own record for the highest goal difference at the halfway point of plus 37, the same they managed in 2012/13, the season they last won the Champions League.
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