Both Marko Arnautovic and Manuel Lanzini were the catalysts for the best day of David Moyes' time as the Hammers manager, as the front two were rampant on a home side who started the match with more energy, only to be pulverized in the end.
Marko Arnautovic firing the Hammers ahead just 15 seconds into the second half.
Huddersfield responded well, with Lolley admirably levelling.
The home side were given brief hope as the half time whistle approached when Joe Lolley equalised with a delightful finish as West Ham's defenders looked on.
A fourth goal arrived just four minutes later, Arnautovic this time running directly at the heart of the Huddersfield defence and nearly finding a way through. It was his mistake that gifted West Ham an opening goal when the visitors had been unable to create anything in the final third, though the midfielder could and did complain that Jonas Lossl put him under pressure with a short ball to the edge of the area. The first is an individual mistake that should never happen.
A long ball from Angelo Ogbonna was flicked onto the Austrian by Cheikhou Kouyate, he lifted it over Tommy Smith and lashed beyond Lossl to restore West Ham's lead.
On his first start in the PL he cut inside from the right and curled a beauty into the far corner with his left foot. 1-1.
West Ham did make it 3-1 soon after as Lanzini raced clear and fired across goal into the bottom corner.
West Ham are up to a season-best 11th in the Premier League after securing a stunning victory at Huddersfield this afternoon.