An own goal from Thiago Cionek and M’Baye Niang’s first strike for Senegal earned Aliou Cisse’s side a 2-1 victory in Group H.
Senegal upset Poland with a 2-1 Group H victory in Moscow that owed plenty to poor mistakes from the European nation.
Poland were widely expected to qualify for the knockout rounds but after suffering a seventh loss in their last nine World Cup matches, FIFA’s eighth-ranked team are in danger of making an early exit.
Thiago Cionek’s own goal, the defender deflecting in a shot from Everton’s Idrissa Gueye, handed Senegal the lead in the 37th minute.
The Lions of Teranga doubled their lead when M’Baye Niang took advantage of a mix-up between Grzegorz Krychowiak and Wojciech Szczesny to finish with ease.
Adam Nawalka’s side set up an exciting finish when Krychowiak somewhat made amends for his error by heading home a Kamil Grosicki free-kick, but they could not find a late leveller.
Poland will need to make amends when they take on Colombia – who surprisingly lost to Japan on Tuesday – while Senegal have qualification for the next phase in their sights.