The Terriers boss, who spent seven years on the Lancashire coast as a player then later a manager, inflicted Blackpool's first home defeat of the season while moving his current team up to second.
Grayson went back to the home of his former employers for the first time since his departure for Leeds in 2008, and it was clear long before Lee Novak's 13th-minute opener that Ian Holloway's men were in for a difficult evening.
A direct approach had troubled centre-back pairing Alex Baptiste and Ian Evatt from the off so it was no surprise to see Novak profit from a James Vaughan flick-on to break the deadlock.
The hosts were back on level terms just 14 minutes later, though, when the relatively subdued Thomas Ince set up ex-Huddersfield forward Gary Taylor-Fletcher for the equaliser.
However, Grayson's men found themselves back in front again when Oliver Norwood's inviting free-kick was headed home by Vaughan. And Norwood himself gave Huddersfield a two-goal cushion less than three minutes after the break with another set-piece which eluded everyone before flying into the far corner.
Blackpool went into the game having dropped just five points from their opening six encounters but they failed to seize the initiative on a wet evening as the visitors took a deserved lead.
Adam Clayton and Daniel Ward had already gone close and the hosts failed to heed the warning as Vaughan headed the ball into Novak's path and he coolly slotted the ball past goalkeeper Matt Gilks.
Ince has turned in a series of eye-catching performances to underpin Blackpool's strong start and he was instrumental in the leveller, bamboozling Anthony Gerrard before sliding the ball across for Taylor-Fletcher, who just had to prod home.
Stephen Crainey nearly picked out Nathan Delfouneso moments later as the Seasiders began to grow into the game, but Grayson's men delivered a killer blow on the stroke of half-time.
A Norwood free-kick from the right was begging to be thumped home and Vaughan obliged with a header in front of the stranded Gilks.
Holloway's half-time words were still ringing in his players' ears when former Manchester United midfielder Norwood curled in a third. The set piece specialist's centre was aimed towards Vaughan, but the ball evaded him and Gilks was left grasping air as the ball ended up in his net.
That prompted Blackpool to bring on substitutes Matt and Kevin Phillips, with the former firing just wide, while Delfouneso should have reduced the deficit when he blazed wide.
It could have turned into a thrashing, though, had the offside flag not twice denied Vaughan from grabbing his second goal.
But Huddersfield had enough to coast to a victory which will have been particularly sweet for Grayson, whose Leeds side crashed to a 5-0 home defeat to Blackpool last season.
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- James Vaughan
- Oliver Norwood