After Arsenal’s goalless draw with Newcastle earlier in the week, the chance was there for Pep Guardiola’s side to cut the gap to the Gunners at the top, and they did just that as Mahrez moved them to within five points of the Premier League leaders.
The Algerian had a tap-in after a great ball from Jack Grealish, and that proved enough with Chelsea unable to mount any real late charge. They remain tenth in the table, as close to the relegation zone as the top four.
Chelsea were forced into two changes before 20 minutes had been played at Stamford Bridge, Raheem Sterling forced off against his former club with an apparent hamstring injury before Christian Pulisic trudged off shortly afterwards.
That did not dishearten the Blues though and they were the better side for much of the half. Pulisic’s replacement Carney Chukwuemeka came closest to opening the scoring before the break, as his effort from just outside the box bounced back off the inside of the post.
City offered very little in the first-half but they flew out of the blocks and made a brilliant start to the second. Erling Haaland dragged an effort wide, before Nathan Ake nodded a header against the bar and Kevin De Bruyne was denied from distance by Kepa.
The goal felt inevitable and it came just after the hour mark, City’s two changes in wide areas combining. Grealish played a brilliant first-time ball across the face of goal, and Mahrez was there at the back post for the simplest of finishes.
City barely had an attack after taking the lead, content to sit back in their shape and hold on to what they had. Graham Potter replaced a far from pleased Pierre-Emerick Aubameyang, who was brought on for the injured Sterling early on, but the changes were unable to inspire the hosts to an equaliser.