Substitute Patrik Schick gave Bayer Leverkusen their first Champions League victory of the season as they beat Jose Mourinho's wasteful Benfica.
The Portuguese side squandered several chances in Lisbon before the Czech forward broke the deadlock in the 65th minute.
Schick's initial effort was saved by Anatoliy Trubin, but Benfica failed to clear their lines and the ball fell kindly again for Schick to head home.
Mourinho's side had several opportunities to find an opener themselves, with both Dodi Lukebakio and Nicolas Otamendi hitting the woodwork in the first half.
In a frantic few minutes before the break, Lukebakio and Otamendi also had strikes saved by former Brentford keeper Mark Flekken, while Loic Bade made a vital block to stop an effort from Vangelis Pavlidis.
The Greek striker, who had scored five goals in his last four home appearances in the competition, wasted another golden opportunity after the restart when he was unable to round Flekken.
Benfica, who have now lost all four of their games in the Champions League this season, ended the game with 21 shots to Leverkusen's seven.
Mourinho's team are 35th in the 36-team league phase, while Leverkusen moved up to 21st.
Schick scored eight minutes after coming off the bench to replace Christian Kofane
Watch highlights of every Champions League game from 22:00 on Wednesday on BBC iPlayer and the BBC Sport website and app.
There will also be a Champions League Match of the Day on BBC One on Wednesday, from 22:40 to 00:00.
