RB Leipzig missed the chance to move to second when they suffered a shock 2-1 home defeat by Bundesliga basement side FC Cologne.
Schalke 04 jumped up to third with a 2-0 win at 10-man Bayer Leverkusen.
Leipzig seemed headed for a narrow victory after taking a fifth-minute lead through Jean-Kevin Augustin but were stunned by two late goals against a Cologne side who remain bottom.
The visitors' Vincent Koziello and Leonardo Bittencourt struck in the 70th and 77th minutes respectively to secure an unexpected win - only their fourth in the league this season - that left Leipzig down in sixth place.
"We deserved to lose. Our performance in the second half wasn't like us at all," Leipzig's Sweden winger Emil Forsberg said.
"We went into the lead and should have come away with the three points."
Schalke improved their chances of a top-four finish with victory at Leverkusen.
A simple sidefooted goal by Guido Burgstaller in the 11th minute and Nabil Bentaleb's penalty in the 89th after Panagiotis Retsos brought down Breel Embolo proved the difference.
Leverkusen faced an uphill battle after midfielder Dominik Kohr picked up a second yellow card in the 38th for a late challenge on striker Embolo and was given his marching orders.
"We came here with the mentality that we needed the three points. We fought like lions and I think we deserved the three points," Schalke striker Franco Di Santo said.
With pacesetters Bayern Munich having extended their lead to 20 points despite being held 0-0 at home to Hertha Berlin on Saturday, the rest are battling for Champions League places.
Borussia Dortmund can narrow the gap at the top at home to mid-table FC Augbsurg on Monday and boost their top four hopes in a tight battle with two points separating second and sixth.
Dortmund have 40 points along with Schalke, with Eintracht Frankfurt, who lost 1-0 at VfB Stuttgart on Saturday, on 39 while Leverkusen and Leipzig are level on points with 38.
