Bayern Munich and Manchester Ciy sealed their qualification to the knockout stages of the Champions League, where they will accompany Sevilla, Chelsea, Barcelona and Juventus, who also achieved the pass on Tuesday.
The outlook for Liverpool is more complicated after their unexpected defeat against Atalanta (0-2).
Group D is red hot after Ajax's triumph against Midtjylland (3-1).
Two points separate Liverpool, with nine, from Ajax and Atalanta, second and third with seven points.
City maintained their great record in the group stage of the Champions League, where they played their 15th game without losing, with 12 wins and three draws.
The latter against Olympiacos (0-1) settled on a goal from Foden in the 36th minute.
The young English midfielder received an excellent heel pass from Sterling from inside the box.
Then he defined with a great dry shot.
Olympiacos tried, but City maintained their lead to secure their place in the round of 16 of the competition.
The Spanish Eric García and Ferrán Martínez did not play for a minute in Greek lands.
The City, with an irregular trajectory in the Premier, where it is 13th in the standings, counts by victories each match it has played in this Champions League.
BayernNeuer, Alaba, Chris Richards (Javi Martínez, min. 78), Boateng, Benjamin Pavard (Lucas, min. 62), Serge Gnabry (Sane, min. 61), Müller, Leon Goretzka, Kingsley Coman (Douglas Costa, min. 78), Marc Roca and Lewandowski Salzburg, Cican Stankovic, Wöber, Rasmus Nissen Kristensen, A. Ramalho, Ulmer, Junuzovic (Karim Adeyemi, min. 70), Mergim Berisha, Dominik Szoboszlai (Luka Sucic, min. 70), Mohamed Camara, Enock Mwepu (Majeed Ashimeru, min. 70) and Sekou Koita
51: Wöber (pp).
72: Mergim Berisha.
Referee Orel Grinfeld Yellow cards Neuer (min. 23), Marc Roca (min. 47), Sekou Koita (min. 57) and Mohamed Camara (min. 93) Red cards Marc Roca (min. 65)
Bayern subdued Salzbugo (3-1), although they showed some symptoms of fatigue in the second half.
The first goal didn't come until the 43rd minute, when Lewandowski made it 1-0.
Something with history, since the Polish striker reaches 71 in the Champions League and equals Raúl González, Madrid forward.
Coman, with the help of a defender, and Sané scored the second and third goals.
Berisha closed the gap.
Counting the European Super Cup that they beat Sevilla, Bayern have 16 consecutive wins in continental competition.
Atalanta gave the bell by beating Liverpool (0-2) at Anfield.
Bad encounter of the English champion, who suffered a lot before the shameless game of the Italians.
Argentine Papu Gómez led his team to victory.
He participated decisively in both Atalanta goals.
In the first place, giving the goal pass to Ilicic in the 60th minute. Papu then crossed the area for Gosens to make the final 0-2 four minutes later.
With the triumph of Ajax against Midtjylland (3-1), the group is in a real handkerchief.
Liverpool, Ajax and Atalanta will fight for the two places that give access to the round of 16.
Good victory for Porto against Marseille (0-2), which brings them very close to the classification, although Olympiacos still have some options.
Marseille, bottom, added their defeat number 13 followed in the maximum continental competition.
He still has a chance to play the Europa League.