Birthday boy Bilic turned 49 yesterday and celebrated with a victory which might just have saved his job.
But it came in the most fortunate of circumstances with the Terriers, who had not conceded a single goal before this game, letting in a corker.
There was little Jonas Lissl could do when Pedro Obiang’s harmless 72nd-minute shot looped up off Mathias Jorgensen’s back and beat him by going in off the far post.
But as unexpected as it was considering the Hammers had huffed and puffed to no avail until then, it could just turn their season around.
A month ago, Team GB won World Championship relay gold in this stadium, but it was West Ham’s turn to pick up the baton in their first game of the season here.
And when supersub Andre Ayew bagged a second the Hammers were finally out of the blocks for their first win of the campaign – and you could see the pressure lift from Bilic’s shoulders.
The sacking of Frank ds Boer earlier in the day must have left him glancing nervously over his shoulder, if he wasn’t already after three straight defeats.
Crystal Palace acted with utter ruthlessness in axing their dodgy Dutchman. But the Hammers actually started this game BELOW them in the Premier League.
Bilic added to the sense he was skating on thin ice by openly criticising chairman David Sullivan’s transfer policy in the build-up to this game.
But he told his players to do their talking on the pitch, and recalled striker Andy Carroll almost provided the perfect response inside two minutes.
Playing for the first time in five months, Carroll held off his marker and swung in a low cross which Cheikou Kouyate was inches from converting.
Then it was Javier Hernandez getting into the act, hitting the woodwork when he probably should have scored after another great cross, this time from Michail Antonio.
Lossl saved a header from James Collins which deflected off his marker’s back, and Carroll, causing all sorts of problems, headed a over.
There was pace and purpose from Antonio, fire and fury from Carroll. Controversy too with Winston Reid not even booked after accidentally kicking Philip Billing in the face as he fell backwards.
But the Terriers didn’t own the division’s best defensive record for nothing, and by half time, with all the noise already sucked out of the building, they had faced only one shot on target.
The Hammers were straight back at it after the break, raining in crosses for Carroll to chase. But it was all a bit too predictable.
Huddersfield had offered little threat themselves, and it took until the 55th minute for Billing to force Joe Hart into a save with an optimistic effort from 30 yards.
But the longer it went goalless the more you could sense the tension in the air. Bilic had to act, and he did so by throwing on Ayew for Hernandez.
The Mexican, already a popular figure here, had looked like a fish out of water trying to run the channels next to Carroll in a three-man front line.
But the home fans did not like that decision, and responded with a chorus of boos, prompting the away supporters to pipe up with a chant of: ‘You’re getting sacked in the morning’ at Bilic.
It was desperate stuff. But just when it seemed like the game was fizzling out, West Ham finally made the breakthrough with one of the flukiest goals you will ever see.
Obiang’s shot was sailing well wide until it hit Jorgensen and looped up and over a stranded Lossl before going in off the post.
When Ayew made it two soon afterwards it looked like being Bilic’s day. But there was still time for Tom Ince to hit the crossbar for Huddersfield.
And you could feel the relief among the home fans in the 56, 977 crowd as the final whistle went.
