Huddersfield, impressive here in a victory against Manchester United and a slender defeat to Manchester City more recently, failed to trouble their opponents until Laurent Depoitre popped up in the second minute of injury time.
Despite being in complete control of the ball, the Blues struggled to truly create any openings until their breakthrough moment a quarter of the way through the contest.
Bakayoko had to beat both the angle and Lossl, which he managed to do with a little help from Chris Lowe on the line in what may go down as an own goal.
Chelsea moved from first gear into second for the remainder of the first half, coming close to adding a second through an N'Golo Kante drive over the bar from range and a glanced Bakayoko header towards the back post.
The second did arrive before the interval, however, with Willian peeling off his man and converting Marcos Alonso's left-sided cross to give Town a mountain to climb.
Another sloppy error at the back almost had the champions in for a third before the half-time whistle sounded, only for Pedro to come out second best when through one on one with Lossl.
Two goals became three soon after the second-half restart, though, thanks to a curled Pedro finish from 15 yards after being left in acres of space by the below-par hosts.
Hazard was then thwarted by the feet of Lossl as a Chelsea side boasting the second-best away record in the division pushed for another goal, but Town did eventually offer something a little more in attack later in the match.
Pedro shot wide from a good position soon after, and it would be Huddersfield who registered the fourth goal of the night as substitute Depoitre made a clean connection to head past Courtois from the final act of the game.
The lack of clean sheet aside, a positive night for Chelsea ends with them level on points with Man United in second place.
Huddersfield Town (4-2-3-1): Lossl; Smith, Jorgensen, Schindler, Lowe (Hadergjonaj 67'); Hogg (Whitehead 46'), Mooy; Williams, Ince, Kachunga; Mounie (Depoitre 74')
Chelsea (3-4-3): Courtois; Azpilicueta, Christensen (Ampadu 80'), Rudiger; Moses, Kante (Drinkwater 71'), Bakayoko, Alonso; Willian, Hazard (Batshuayi 67'), Pedro