They travelled by train, plane and bus.
Little Devils: Crawley fans were determined to enjoy their day out
They took over service stations on the M6 and M40, and one convoy of 27 coaches caused traffic chaos on the approach to the ground. Mayor Lee Burke went in full regalia.
Josh Thomas, a marketing man, had jetted in from Hong Kong, and Paul Prendergast was in full voice, despite travelling without his lucky cowbell.
Pride of Sussex: Crawley Town fans soak up the atmosphere
He had taken it to every other FA Cup game this season, starting in the fourth qualifying round at Newport.
But United said he could not take it into their ground.
'They said it would be viewed as an offensive weapon,' he said.
Glasses half full: Crawley fans happy to see their side give United a mighty scare
But Crawley's fans were determined to enjoy it. They were seated and singing for an hour before kick-off.
Manager Steve Evans added his vocal input after United took the lead.
Sing up: It almost turned into the Theatre of screams for United
Evans, who grew up only seven miles from Sir Alex Ferguson, makes his fellow Glaswegian look like a choirboy, with touchline bust-ups and a suspended prison sentence for doctoring contracts at previous club Boston.
Travelling circus: Crawley almost made Rooney and company look like clowns
While Ferguson stayed in his seat, Evans and assistant Paul Raynor were a whirlwind of activity.
Raynor complained aggressively to the fourth official when a challenge by Rafael went unpunished. It was not the normal submissive behaviour of a plucky underdog.
Loud and proud: Crawley's gutsy, attacking football won them plenty of admirers
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