Chelsea's Olivier Giroud, left, celebrates with Chelsea's Willian after scoring his side's fourth goal during the English Premier League soccer match between Chelsea and Everton at Stamford Bridge stadium in London, Sunday, March 8
Chelsea claimed its biggest Premier League win under Frank Lampard on Sunday with a 4-0 victory over Everton strengthening its grip on fourth place.
Mason Mount, Pedro, Willian and Olivier Giroud scored as Everton manager Carlo Ancelotti endured a wretched first return to Stamford Bridge since his two-year tenure leading Chelsea.
Billy Gilmour again provided the spark, with the 18-year-old midfielder more than backing up his star performance in Tuesday's 2-0 FA Cup win over Liverpool.
He proved the catalyst for Chelsea's first two goals, in a full Premier League debut of composure and class.
The hosts were without seven first-team regulars but Gilmour ensured Chelsea never missed a beat, despite the absence of international midfielders N'Golo Kante, Mateo Kovacic and Jorginho.
Ancelotti led Chelsea to their maiden domestic double in 2010 and was afforded a warm reception on his west London return. If the Italian enjoyed that welcome, he must have hated everything else to follow.
Mount's acrobatic half-volley forced Jordan Pickford into an early reaction stop, as Chelsea dominated from the start.
The home team hardly had to wait to break the deadlock either, with Mount ending his three-month goal drought in style in the 14th minute in a move started by Gimour's pass.
Mount fed Pedro out wide and the Spaniard cut in off the left and threaded the ball back inside for the midfielder to control on the half-turn and then drill home.
Seven minutes later, Chelsea doubled its lead, with Gilmour again at the heart of it.
The ball was fed through to Giroud, who laid it off to Ross Barkley. The former Everton midfielder threaded Pedro through on goal and the forward just about beat the offside trap, steadied himself and then slotted past a helpless Pickford.
While the assists and finishes might have been ending up elsewhere, Gilmour was always the player getting Chelsea going.
Chelsea's dominance extended to the point where Everton's sole chance of the first half came from a mistake.
Marcos Alonso's loose pass let Richarlison cut away, but Dominic Calvert-Lewin wasted his attempt at a cute finish, scuffing wide when he tried to dink over goalkeeper Kepa Arrizabalaga.
An afternoon of extreme Chelsea comfort was sealed after the interval, when Willian struck crisply into the bottom corner from 20 yards (meters) in the 51st.
Giroud tapped in Willian's corner under precious little resistance, completing the rout in the 54th.
