Oscar (7) stroked in the opener, Diego Costa (59) – with his eighth goal in six Premier League games since signing from Atletico Madrid for £32million – knocked in a second and Willian brushed in a third (79) to maintain the Blues’ 100 per cent home record.
The comprehensive win leaves Chelsea three points clear at the summit as they chase a first Premier League title since 2010.
The Londoners defeated Manchester United 1-0 in Mourinho’s first league game at the Chelsea helm in 2004 – and it took them little time at all to move into that scoreline against a Villa side thumped 3-0 at home by Arsenal in their previous match.
Oscar, who netted his first goal of the campaign in the Capital One Cup win over Bolton in midweek, converted Willian’s pass to score from six yards
Willian had seen his initial attempt pawed away by Brad Guzan having been found by Branislav Ivanovic down the right, but the Brazilian remained alert and squared the rebound into his countryman’s path.
Winger Willian almost went from provider to scorer after 15 minutes, but, after latching onto a beautiful back flick from Costa, saw his shot clip off Nathan Baker and hit the side-netting.
Cesc Fabregas was pulling the strings in the centre of the park – a delightful slide-rule pass just evaded buccaneering right-back Ivanovic and nestled into Guzan’s gloves – and the former Barcelona man skewed a strike wide soon after as the hosts continued to control the contest.
Chelsea’s next two attempts were both headers – Costa flicking an enticing cross from the ever-lively Willian into Guzan’s mitts and Ivanovic nodding a Fabregas corner over the bar – before Costa and then Willian whipped in shots too high and wide to test Villa’s American stopper.
The visitors were finding it tough to get a foothold and chances were at a premium, too, with Chelsea skipper John Terry – who made his Blues debut against Villa in a League Cup tie in 1998 – blocking crosses, and a Fabian Delph snapshot, at will.
The Midlanders’ only moments of note came when left-back Aly Cissokho clipped wide from a corner under pressure from Nemanja Matic, and frontman Andreas Weimann was crowded out by the Blues’ rearguard before he could get a strike away.
And after Willian fired wide, official Phil Dowd – the referee when Villa were thumped 8-0 at Stamford Bridge in December 2012 – brought an end to a first period in which Gary Cahill was booked for a cynical swipe on Gabriel Agbonlahor.
Villa had the first attempt of the second half – England new boy Delph rasping a 25-yard strike wide of Thibaut Courtois’ sticks – and were getting a modicum of joy in Chelsea territory with the pace of Agbonlahor and the graft of Kieran Richardson.
Baker headed Ashley Westwood’s free-kick onto the roof of the net but Chelsea responded through Costa, who first nodded an Ivanovic centre into the grateful arms of Guzan and then scored the hosts’ second.
Terrific interplay from Eden Hazard and Willian down the left resulted in Cesar Azpilicueta chipping into the penalty area and Costa – who amassed 27 goals in all competitions for Atletico last term – heading his side further in front.
Mourinho’s men were turning the screw, with Oscar seeing his poke past Guzan cleared off the line by Cissokho, Matic quelled by Philippe Senderos as he tried to get his head to a Fabregas in-swinger, and Costa narrowly avoid making contact with Hazard’s pearl of a ball into the box.
Hazard had danced past Alan Hutton to fashion Costa’s chance, but Villa’s right-back – back in Paul Lambert’s good books and the recent recipient of a new three-year contract – surged upfield shortly after and tested Courtois with a low drive.
However, the Scot saw his side drop further behind on 79 minutes when Costa’s effort was parried by Guzan, flicked off the unlucky Cissokho and livewire Willian was presented with a simple tap-in to make it three.