Grzegorz Krychowiak and Dimitri Barinov capitalised on Bayer Leverkusen's blunders to give Lokomotiv Moscow a 2-1 win in their Champion League Group D opener on Wednesday.
Krychowiak profited from some carless play from Leverkusen's players in their own half to give the Russian side the lead in the 16th minute at the BayArena.
An own goal from Benedikt Howedes got the hosts back on level terms but Barinov punished another Leverkusen mistake to seal the win for the visitors.
Lokomotiv's victory was their first away from home in the Champions League since a 2-1 win at Galatasaray in the 2002-03 group stage.
The Russian side took the lead against the run of play when Leverkusen's Leon Bailey sloppily lost possession in his own half from a throw-in.
Lokomotiv reacted quickly as Polish midfielder Krychowiak latched on to a clever pass from Joao Mario and struck a controlled finish past Lukas Hradecky in the Leverkusen goal.
It only took the Bundesliga outfit nine minutes to find an equaliser with Howedes, the only German player in the Russian side, diverting Charles Aranguiz's shot from Lars Bender's cross into his own net.
However, Leverkusen's Dutch coach Peter Bosz was left shaking his head eight minutes before half-time after a mistake from goalkeeper Hradecky saw the home side fall behind again.
Hradecky's casual pass from the edge of the penalty area was seized upon by Barinov, who lifted the ball over the hapless Finland international.
Leverkusen continued to enjoy the bulk of possession and chances after the interval but were unable to find a way past a defiant Lokomotiv keeper Guilherme.
What does it mean? Lokomotiv learn lessons
With European heavyweights Juventus and Atletico Madrid the two other teams in the group a good start to the campaign was essential for both sides if they are to have any hope of making the knockout phase.
Lokomotiv meekly lost all three of their away games in the group stage of last season's Champions League but looked to have learned their lesson.
If the unfancied Russian side can make home advantage count in their three matches in Moscow they might be the group's surprise package.
Howedes impresses on home soil
A World Cup winner with Germany in 2014, 31-year-old defender Howedes was desperate to remind everyone in his homeland he was not just a memory from a previous era. The centre-back scored an unfortunate own goal but quickly put the disappointment behind him to produce a superb defensive display.
Horror show from Hradecky
It was not a night to remember for Leverkusen's man between the posts. The Finn has bags of experience for club and country but was punished for a lack of concentration when he presented Lokomotiv a goal on a silver platter. He looked shaky for the rest of the contest.
Leverkusen return to Bundesliga action this Saturday when they host Union Berlin, while Lokomotiv make the long trip to Orenburg in the Russian Premier League on Sunday.