Town substitute Laurent Depoitre headed home a fine goal deep in stoppage time but it was a mere consolation for David Wagner's side.

Not since the Blues won 4-0 at West Brom in November had they shown last season's title-winning pedigree, but, masterminded by Willian, they looked back to their slick, efficient best once they had taken the lead late in the first half.

Chelsea's first attempt on target resulted in the opening goal, with Eden Hazard sparking the move which broke the deadlock.

Hazard's flick set Willian free in a central position just outside the penalty area and the Brazilian's diagonal pass was clipped neatly home by Bakayoko from six yards, with defender Chris Lowe's desperate bid to block the ball on the goalline in vain.

Huddersfield had chased and harried throughout the first half but had also enjoyed decent spells of possession without carving out any clear-cut chances.

The home side's best moment before the break came early on when a sweeping move involving skipper Tommy Smith, Elias Kachunga and Aaron Mooy saw the latter's volley from the edge of the box blocked by Cesar Azpilicueta.

Chelsea had been well marshalled for most of the first period. Ngolo Kante blazed a shot over in the 38th minute and Bakayoko directed Willian's cross wide off his shoulder.

But Chelsea doubled their lead in the 43rd minute. Azpilicueta's cross-field pass picked out Marcos Alonso wide on the left and the Spaniard's superb cross evaded Lowe at the far post and was headed home by Willian.

Town boss Wagner sent on fresh legs for the second half as Dean Whitehead replaced Jonathan Hogg, but it made little difference.

Chelsea extended their lead in the 50th minute thanks to another assist from Willian and more good work from Alonso.

Willian touched Alonso's cross back into the path of Pedro on the edge of the area and the latter crashed a right-footed shot into the top corner.

Jonas Lossl denied Hazard at the near post after the Belgian had snaked his way into the area before Town eased the relentless pressure with a rare foray on goal themselves when Tom Ince's effort was headed clear of goal by Andreas Christensen.

Mathias Jorgensen also lifted the home faithful with a long-range effort, but home pressure was not to last as Hazard brilliantly set up Pedro twice in as many minutes, only for the Spaniard to pull both efforts wide.

Conte sent on teenager Ethan Ampadu for his Premier League debut in the closing stages, while a long-range shot from Town midfielder Danny Williams was deflected narrowly wide off Depoitre.

Depoitre, a late replacement for Steve Mounie, headed brilliantly home in time added on from fellow substitute Florent Hadergjonaj's excellent cross.