Bayer Leverkusen narrowed the gap on Bundesliga leaders Bayern Munich to 10 points, for 24 hours at least, as they came from behind to beat Stuttgart 2-1 at the BayArena.
Moritz Leitner gave the visitors the lead in the 12th minute, but Stefan Kiessling and Eren Derdiyok turned the game on its head to move Leverkusen four points clear of Borussia Dortmund.
Stuttgart fell to their third defeat in a week to remain too close to the relegation zone for their liking.
Schalke made it two wins from two at the start of 2014 as they saw off 10-man Wolfsburg 2-1 to move into fourth place.
Felipe Santana put the hosts in front with a bit of luck in the ninth minute and Wolfsburg's hopes appeared to be dashed when Daniel Caligiuri was given his marching orders early in the second half.
Nevertheless, Dieter Hecking's men levelled through Maximilian Arnold, but Kevin-Prince Boateng snatched the points for the Royal Blues nine minutes from time as his side kept the pressure up on the Bundesliga's leading teams.
Hannover coach Tayfun Korkut celebrated securing two wins out of two as a Mame Diouf double helped his side beat Borussia Monchengladbach 3-1.
Artjoms Rudnevs headed Hannover in front before Diouf struck. Peniel Mlapa pulled a goal back for Gladbach, but Diouf's second sealed Hannover's win to lift the Reds up to 10th in the table, where they are six points off the top six.
Hamburg dropped deeper into relegation trouble as they slumped to a 3-0 loss at Hoffenheim, their fifth straight defeat.
Goals from Roberto Firmino, Niklas Sule and Andreas Beck secured victory for the hosts which eased their relegation fears and and left their opponents in the bottom three.
The emphatic win also saw Hoffenheim rid themselves of the Bundesliga's worst defensive record.
South Korea internationals Park Joo-ho and Koo Ja-cheol combined to keep Mainz in the hunt for a place in Europe next season with a 2-0 win over Freiburg.
Park struck first midway through the first half and Koo sealed victory late on for Thomas Tuchel's men, who are now breathing down the necks of sixth-placed Wolfsburg.
Augsburg made it seven games unbeaten with a 3-1 win over 10-man Werder Bremen on Saturday to boost their chances of European qualification.
An own goal from Jan-Ingwer Callsen-Bracker gave Bremen an early lead, but the rest of the game belonged to the hosts, who levelled within eight minutes through Tobias Werner.
Bremen were reduced to 10 men just before half-time when Santiago Garcia picked up his second yellow card and Augsburg needed just four minutes of the second half to go ahead, with Halil Altintop scoring. Andre Hahn then stole in to make it three and take Augsburg to within two points of sixth-placed Wolfsburg.