Following a defeat at Sunderland the Hammers could not afford another slip-up in the quest to reach the heady heights of the Premiership.
Emerging to the Star Wars theme they soon launched themselves into the ascendancy and by half-time were on a different planet to the battered visitors.
As early as the fifth minute Bobby Zamora forced Clayton Ince to turn his sizzling, angled 12-yarder aside, and Michael Carrick's consequent corner fell perfectly for Marlon Harewood to rise at the far post and head the Hammers on their way.
And on 20 minutes, the former Forest striker had the keeper picking the ball out of the net again when he collected from Nigel Reo-Coker, spun off his marker, and unleashed a rising 18-yarder into the top left-hand corner for his 22nd goal of the season.
Shortly afterwards, only the well-placed Alex keeper denied the striker the match ball and after Zamora fired narrowly wide, Kevin Horlock also saw his long-range effort saved.
But ten minutes before the break, there was to be no stopping Reo-Coker's powerful, rising 20-yard shot under Ince's left-hand angle after the tenacious, overlapping Jon Harley swept the ball back from the corner flag.
Having just seen his former Wimbledon team-mate bag his second West Ham goal, Joel McAnuff then netted his first goal for his new club when he weaved away from a posse of pursuers before rounding off a sensational solo run with a low angled 20-yard shot that skidded in off the base of the far post.
McAnuff might then have had a second just after the interval, but Ince steered his stinging shot over and then Zamora went inches wide.
On the hour, though, a thundering challenge on McAnuff went unpunished and Crewe broke upfield.
Steve Jones at last gave their 507 travelling fans something to cheer as she fired a low 15-yard whot past the exposed Stephen Bywater to the disgust of the Eastenders who saw Tomas Repka's furious protests earn him a 14th yellow card of the season.
Ten minutes later, Jones was on the mark again when he ghosted behind the complacent West Ham defence and rounded Bywater before slotting home from a seemingly impossible angle.
That added some respectability to what had earlier looked like becoming an absolute rout but that was about as good as it was to get for a Crewe side who saw Ince stretchered away after he fell awkwardly clearing his lines on a night to forget for the keeper.