Bayer 04 Leverkusen had to settle for second place in Group E despite Eren Derdiyok's 79th-minute equaliser at KRC Genk.
The German side went into matchday six a point clear at the top of the standings and already certain of their place in the UEFA Champions League round of 16 for the first time since 2004/05. Their hopes of holding on to top spot suffered a setback when Jelle Vossen volleyed the Belgian title holders into a 30th-minute lead and, despite Derdiyok's well-worked leveller, the draw allowed Chelsea FC to overtake Leverkusen to win the section.
Genk, cast adrift at the foot of the group, began nervously. Twice they ceded possession in central areas early on – always a danger with players of the calibre of Michael Ballack and Lars Bender ready to pounce. The home midfield, and Fabien Camus in particular, grew in confidence as the first half unfolded, while Sidney Sam and Derdiyok connected well for a Leverkusen team struggling to find the final ball.
Instead it was Vossen who struck first, meeting Dugary Ndabashinze's right-wing cross with a volley from just inside the penalty area that swerved inside Bernd Leno's left-hand post; the 22-year-old's second goal of the group stage.
Camus shot into the side netting and Jeroen Simaeys headed narrowly wide from a corner as the Belgian champions sought to add to their advantage before half-time, and the pattern continued into the second period. With Ndabashinze a constant threat, Leverkusen's hopes of finding a way back into the match looked to be slipping away.
Instead they nearly fashioned an equaliser in the 55th minute, the ball running free to Michael Ballack 20 metres out but the midfielder's aim was fractionally awry, his shot clipping the top of the crossbar. Derdiyok, previously shackled by Anthony Vanden Borre, then slipped his marker and almost converted an André Schürrle centre.
The Swiss striker made no mistake ten minutes later as he slotted in his sixth goal in four outings, converting Sam's low cross with the Genk defence for once caught out. Both sides looked for a winner, substitute Elyaniv Barda and Thomas Buffel forcing fine late saves from Leno, and that was a close as either team came. Despite finishing bottom of the group Genk remain unbeaten at home having drawn all three matches, while Leverkusen can now look forward to the 16 December draw.