Pedro slotted in Chelsea's fourth-minute opener, their 1,000th home PL goal, after N'Golo Kante dispossessed Jean Michael Seri, surged forward and played in the Spaniard.
Olivier Giroud went close as the home side controlled the first half, but Calum Chambers twice forced Chelsea goalkeeper Kepa Arrizabalaga into action for Claudio Ranieri's visitors after the break.
But substitute Loftus-Cheek wrapped up the win after being set up by Eden Hazard with eight minutes left, putting Maurizio Sarri's side on 31 points.
Fulham remain bottom of the table on eight points.
Chelsea: 5 Dec v Wolves (A)
Fulham: 5 Dec v Leicester (H)