Eintracht Frankfurt ended a 10-game winless run to dent Bayer Leverkusen's title hopes with a 1-0 win at the BayArena.
Marco Russ scored the only goal on the hour mark but Frankfurt were indebted to goalkeeper Kevin Trapp for preserving their advantage until the whistle.
Joselu missed a penalty that would have made it 2-0 deep in stoppage time but Frankfurt held on to move three points clear of the relegation zone, while leaving Leverkusen seven adrift of Bayern Munich at the top of the table.
Frankfurt started the brighter and almost took the lead when Jan Rosenthal's header hit the post.
The visitors had 60 per cent possession at one stage such was their early dominance, and in the 17th minute Joselu saw his drive kept out by Bernd Leno.
The Eagles continued to press for the duration of the first half, with a Stefan Kiessling effort that was hooked away acrobatically by Carlos Zambrano the only effort of note for the off-colour hosts.
The music changed in the second half with Zambrano getting in a block to deny Robbie Kruse
Son Heung-min and Kiessling both had efforts saved by an increasingly busy Trapp before Frankfurt opened the scoring on the break thanks to a quickly-taken free-kick which caught the Leverkusen defence cold.
Sebastian Jung was sent down the right wing and his cross was met by a determined header into the net from Russ.
Leverkusen moved up a gear and started to lay siege to the Frankfurt goal, Kiessling teeing up Giulio Donati for a shot which Trapp turned behind.
Kiessling then set up Omer Toprak but he missed the target with a header from eight yards, while the Germany striker then saw another header go straight into Trapp's hands.
Leverkusen fought valiantly to get back into the game but Trapp stood firm in the face of the barrage.
Frankfurt could have made it two with the last kick of the game but Joselu's penalty was pushed onto the post by Leno.