Goals from Nicolas Jackson and Enzo Fernandez secured the three points for Chelsea as they beat Leicester City 2-1 at the King Power Stadium.
Maresca received the perfect welcome gift on his return to his former club when Jackson fired the Blues ahead inside the opening 15 minutes of the game.
The Senegal forward fashioned the chance out of nothing after pressing Wout Faes, forcing an error and then tucking his shot into the bottom corner thanks to the return pass from his team-mate Fernandez.
Pressure from Chelsea and the home crowd was piled on Leicester following the early goal and Noni Madueke thought he had doubled the lead before the break, only to see his celebrations cut short by VAR after Marc Cucurella had drifted offside in the build-up.
Leicester responded well as the first 45 minutes came to a close, with Wilfred Ndidi and Kasey McAteer both pulling shots just wide of the target to the dismay of Steve Cooper on the touchline.
Madueke was quickly involved again after the restart – but this time for the wrong reasons.
The Chelsea winger spearheaded a logjam of players that prevented Cole Palmer tapping the ball into an empty net following Mads Hermansen’s parried save to deny Jackson a second.
The miss ultimately did not cost Maresca’s men, who went on to add a second through an impressive diving header from Fernandez to put the game out of reach for the hosts.
Leicester were awarded a late penalty after Romeo Lavia clipped Bobby De Cordova-Reid in the penalty area – but it would only prove to be a consolation goal as Jordan Ayew stepped up to score his third league goal of the season