Brighton produced an encouraging display but Foden's clever finish with his right foot just before the break was just too accurate for Albion keeper Robert Sanchez.
City deserved their victory and it could have been more for the hosts had it not been for a number of decent saves from Sanchez after the break.
Raheem Sterling also missed a penalty for City and Bernardo Silva had an effort crack back off the crossbar and Mahrez also wasted a glorious chance for Pep Guardiola's men just after the break.
But Brighton will be encouraged by the displays of debutant Percy Tau, while Leo Trossard and Alexis Mac Allister also performed well.
Scroll down and click through to see how they rated
5. Dan Burn 7/10
Looked confident again and played well at left back. Showed good character after a troublesome last outing against Wolves
6. Alexis Mac Allister 7/10
Enjoyed his display. Linked the play well and possibly his best performance in a Brighton shirt. Great block on De Bruyne's close range indirect freekick. Had a decent effort on 60 minutes fizz just over the bar
7. Davy Propper 6/10
Encouraging display and grew into the match and getting better with each outing. Played 67 minutes and Albion will need him back to his best for the second half of the season
8. Ben White 6/10
With Bissouma suspended, White moved into the defensive midfield role. Held his position and broke up the play well and kept his passing simple. Tidy performance.