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 Idrissa Gueye, handed Senegal the lead in the 37th minute.
Senegal 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
A slow start at Spartak Stadium saw neither side gain control of the midfield until Senegal had the first clear chance in the 18th minute, Niang dragging a poor effort wide after a break.
The African side – who shocked France on their World Cup bow in 2002, their only previous appearance – gradually started to dominate but the opening goal had a large slice of good fortune.
Patient passing produced an opportunity for Gueye, albeit his 20-yard strike took a huge deflection off Cionek to wrong-foot Poland goalkeeper Szczesny.
Nawalka sent on Southampton defender Jan Bednarek at half-time – Jakub Blaszczykowski making way on his 100th international appearance – as Cionek’s own goal ensured Poland’s 32-year wait for a clean sheet at the World Cup goes on.
Kamil Glik, passed fit despite pre-match fitness doubts, should have got Poland back in the game but he slotted a perfect Piszczek cross wide at the near post.
Dawid Kownacki’s headed attempt was easily saved late on by N’Diaye but the goalkeeper was beaten by Krychowiak’s well-placed header with five minutes to go.
Yet Senegal held on to their advantage in a nervy finish, leaving the Euro 2016 quarter-finalists with plenty to do if they are to qualify from a suddenly wide-open group