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
9. Bernardo 7/10
Played well on the left side of the midfield. Nice defensive work to cut out a wicked cross from De Bruyne at the far post. An excellent cross on 61 minutes that somehow just evaded everyone. Surprised he doesn't get more minutes under Potter
10. Leo Trossard 7/10
Quite influential throughout the match. Clever in possession and also looking to move Brighton forward and start the counter attacks
11. Percy Tau 7/10
Encouraging first half. Showed confidence and good pace on his PL debut. Tidy in possession and always looking to run at Zinchenko. Replaced by Maupay on 67 minutes. Good performance and reliable in possession
12. Solly March 5/10
Didn't quite have the impact he would have wanted. Poor delivery on set pieces and bizarre throw-in across the box led to a penalty that Sterling missed