Town were flat on the restart and Pedro added a third ten minutes from time with a dinked finish over Ben Hamer.
Christopher Schindler's sliding challenge on Marcos Alonso was deemed illegal by Kavanagh and Jorginho craftily waited for Hamer to commit before clipping his spot kick into the opposite corner.
But despite the margin of victory Sarri concedes the Chelsea players are still not playing at the level he wants them to be.
Hazard, like Courtois, was one of the best players at the World Cup and he would be crucial to our chances of doing well in the Premier League and the cup competitions. Hazard drives forward, slipping through Pedro at the ideal moment.
As we know, Kante is not known for scoring goals but he's kept up his record of scoring at least one goal in a Premier League season by getting off to a flyer this afternoon.
New Chelsea boss Maurizio Sarri is adamant that the club will resist any offers for Hazard before the European transfer window closes.
FW Alvaro Morata, 7 - Led the line enthusiastically, held up the ball well when in possession and looked confident enough to suggest the goals that have been missing from his game will come soon enough if Sarri persists with him.
Eyes were obviously on debutants Jorginho and Arrizabalaga and the pair gave excellent accounts of themselves, with the former scoring a cheeky penalty in the first half.
There were occasional signs of hesitancy in defence early on that a stronger team than Huddersfield might have exploited, but to criticise Chelsea beyond that would be harsh. Jorginho stepped up and cooly found the back of the net.
"We are not a physical team and I think the best of the game is the capacity to suffer for 15 minutes".
But the 17-year-old was left out of the matchday squad altogether, with Pedro and Willian starting out wide and Hazard and Victor Moses the options from the bench.
It's a tricky start to the season, and after facing Cardiff on Matchday 3, Huddersfield then takes on Everton, Crystal Palace, Leicester, Tottenham, Burnley and Liverpool.