Borussia Monchengladbach revitalised their Champions League hopes with a 1-0 win at third-placed Schalke on Sunday.
Patrick Herrmann's 35th-minute goal decided the contest, moving the visitors up to sixth place, three points behind Bayer Leverkusen in fourth.
Schalke have a four-point cushion over Wolfsburg in fifth.
At the other end of the table, Hamburg's fears of a first relegation from the Bundesliga increased following a 3-1 loss at European hopefuls Augsburg.
Two goals from Halil Altintop and an Andre Hahn strike had the hosts 3-0 up and, even though Hamburg pulled one back through Heiko Westermann a minute before the break, they could not avoid a 19th league loss of the campaign.
It let them in the relegation play-off spot, five points from safety and only one ahead of second bottom Nurnberg.