Everton boss Ancelotti led Chelsea to the Double in 2009-10 and his first game returned got off to a woeful begin as Mason Mount and Pedro scored inner the opening 21 minutes.
Former Everton midfielder Ross Barkley launched Pedro for the 2nd goal and additionally laid off for Willian to score with a wonderful low strike early in the second half.
Moments later Olivier Giroud poked in from Willian’s move to seal Chelsea’s biggest league win of the season – 5 days after they beat Liverpool in the FA Cup fifth round.
It gave them a five-point cushion in the Champions League places – seventh-placed Manchester United host Manchester City at 16:30 GMT on Sunday – whilst Everton stay in 12th.
The Toffees have improved since Ancelotti took charge in December, however they have taken solely one point from the previous three games – in opposition to Arsenal, United and Chelsea.