Crystal Palace’s winless streak extended to 11 matches as they crumbled under second-half pressure from a resurgent Chelsea.
The Blues took the lead through Estevao after a defensive error, before Joao Pedro doubled the advantage shortly after the interval.
Enzo Fernandez rounded off the scoring with a late penalty, moving Chelsea within one point of the Champions League qualification spots.
For Palace, the defeat intensifies the pressure on the board to find a spark as they slide toward the relegation zone.
Chelsea’s form under Rosenior has been a bright spot in their season, with the manager praised for instilling a more clinical edge in the final third.
The Blues look increasingly like top-four contenders as they enter a crucial period of fixtures in both the league and the FA Cup.