Second-placed RB Leipzig suffered a 2-1 defeat at second-from-bottom Cologne on Tuesday to leave leaders Bayern Munich on the verge of a ninth straight Bundesliga title.
Cologne captain Jonas Hector scored the first Bundesliga brace of his career to end a miserable run of nine league games without a win as Leipzig suffered only their fifth league defeat this season.
"Cologne fought and showed passion," admitted Leipzig attacking midfielder Emil Forsberg.
"We had a few chances, but unfortunately we aren't taking advantage of them at the moment and, of course, we are disappointed about that."
The result means Bayern can go 10 points clear at the top of the league table if they beat Leverkusen at home later.
The club world champions could then be confirmed Bundesliga champions this Saturday at Mainz.
After a goalless first-half in Cologne, the match burst into life after the break.
Germany international Hector headed his side into the lead just 56 seconds into the second half with the visitors' defence napping.
Leipzig hit back on 59 minutes when Malian midfielder Amadou Haidara was left unmarked to launch his shot from the edge of the area past Cologne goalkeeper Timo Horn.
Just 100 seconds after Cologne conceded the equaliser, Hector struck again when he collected a flick just outside the box, held off his marker and fired into the bottom corner.
"Generally, I don't care who scores the goals," Hector told Sky.
"We've not been scoring them in the last few weeks, also because I missed a few chances.
"Today, everyone did everything for the win - that is crucial for the coming weeks," added Hector with Cologne still in one of the automatic relegation places.
The result boosts Cologne's survival hopes with games against mid-table sides Augsburg and Freiburg to come before facing strugglers Hertha Berlin away on the last day of the season.