On a bitterly cold day in West Yorkshire, Alan Pardew's men once again proved that they certainly aren't lacking when it comes to battling against the odds and displaying strength of character, as the magnificent travelling support were rewarded with another splendid victory away from Upton Park.
The win saw Hammers jump into fourth place following Sunderland's draw with Watford, although both Ipswich and Wigan had the chance to leapfrog us again in their evening clash.
Pardew had originally named an unchanged line-up following last week's home win over Rotherham United. However, his plans were disrupted just before kick-off, when the in-form Matty Etherington injured himself in the warm-up.
That meant an unexpected debut for new signing Jobi McAnuff, who stepped off the substitutes' bench to fill in on the left side of midfield, while Anton Ferdinand took up the empty spot in the dug-out, alongside Zamora, who was forced to wait for his Hammers bow given Brian Deane's recent good form.
Once those fun and games had been sorted out, it was time for the real entertainment to begin, and the 13,078 crowd weren't disappointed early on, as both sides attacked the game in a positive frame of mind and created several chances.
After just two minutes, Bradford looked certain to take the lead when Alun Armstrong rose unmarked to meet a corner and headed powerfully towards the top corner. However, Stephen Bywater - playing just his ninth senior game for Hammers, yet his third against the Bantams - stretched across to brilliantly tip the ball round the post.
Four minutes later, it was the visitors' turn to come close, when Carrick's low shot was blocked and Reo-Coker's follow-up was saved by goalkeeper Alan Combe, before Bywater was called into action again when Alun Armstrong beat the offside trap but saw the young Hammers stopper force a corner.
Amazingly, the end-to-end action didn't let up there, as Carrick saw a decent effort parried away for a corner and Harewood's surging run ended with his cross being cleared only as far as Reo-Coker, whose shot came back off the post to leave most in the ground wondering how the game was still goalless with just 15 minutes gone.
Even more surprising was the fact that it then took another 20 minutes before another serious effort on target was registered - and it brought Bradford the opening goal. As a loose ball bounced around in the Hammers' penalty area, Dailly and Repka both hesitated and Gray touched back to Atherton, who curled a tremendous effort past Bywater from the edge of the area.
Moments before half-time, Hammers were handed a glorious opportunity to level the score, when Carrick's cross found Connolly unmarked and onside just six yards out, but the Irish striker headed straight into the arms of a grateful Combe.
Having spent almost the entire first half warming up on the touchline, it seemed likely that Zamora would be introduced fairly early in the second half, and Pardew decided to wait no longer as the half-time whistle blew. Changing both the personnel and the formation, he replaced Deane with Zamora and McAnuff with his former Wimbledon team-mate Adam Nowland, and switched to a 4-3-3, with Harewood pushing forward and Nowland joining Carrick and Reo-Coker in the midfield three.
The change had an immediate effect, as Hammers came out in determined mood and pushed Bradford on to the back-foot, with the pace and power of Zamora causing panic among their back four.
At times it seemed as though the visitors were queuing up to take aim on the Bradford goal. Connolly, Nowland, Carrick, Zamora and Mullins all fired in efforts that were either blocked, saved or flew inches wide and, as the halfway mark in the second period approached, it appeared that the hosts had a fighting chance of hanging on to their lead.
With 25 minutes remaining, though, Hammers finally found the breakthrough. An up-and-under cross from Jon Harley was only palmed out by Combe and Christian Dailly hooked the ball back into the danger area, where Zamora was on hand to head into the roof of the net.
Spurred on by the terrific vocal support, Hammers went hunting for a second and found it with just 12 minutes remaining. Nowland's searching pass found Connolly, whose neat lay-off released Harewood, and the former Nottingham Forest striker became the First Division's leading scorer with his 18th goal of the season - an emphatic strike through the legs of Combe.
The hosts threw on veteran striker Dean Windass in a desperate effort to salvage a point, and they looked to have done so when a deep cross was headed back across goal towards two unmarked attackers at the far post but, having denied the Bantams in the opening minutes, Bywater also had the last word as he bravely scrambled across to palm the ball to safety.
Attention now turns to the FA Cup again and a mouth-watering fifth round tie against London rivals Fulham next Saturday, but Alan Pardew will also have one eye on a third successive away day the following week, when Hammers visit league leaders Norwich City in a game that is likely to have a major impact on our hopes of automatic promotion.