Leeds, turfed out of the Coca Cola Cup by Reading in mid-week, appeared to be heading for another home defeat when Frank Lampard fired West Ham in front midway through the second half. George Graham's side had not forced a single save out of Ludek Miklosko, but took heart from Jimmy Hasselbaink's equaliser and went on to add further, flattering goals in the last four minutes through Alfe Inge Haland and Hasselbaink.
The victory was Leeds' seventh in 10 League outings and left West Ham to reflect on a record of just six wins in 42 visits to Elland Road.
Leeds also scaled an important psychological barrier in that they were without both their captain, the suspended David Hopkin, and the 19-year- old striking prodigy Harry Kewell, absent on World Cup duty with Australia. West Ham were unable to call on Rio Ferdinand, though the pressure on them was so gentle until the crazy last quarter of an hour he would not have aggravated his calf strain unduly.
All the more perplexing, then, that West Ham should have caved in once Leeds upped the tempo. Harry Redknapp's team won at Barnsley on the season's opening day, but has since gleaned a solitary point from a possible 24 on their travels.
Leeds determined to avoid a repetition of the defensive aberrations which gifted three goals to both Derby and Reading, could muster no creative spark in midfield in the first half.
As a result, Hasselbaink and Rod Wallace often had to compete on unequal terms with the towering Ian Pearce and David Unsworth for a series of high balls pumped from the back. In contrast, West Ham looked to exploit the aerial ability of John Hartson, the centre-forward Graham once bought for Arsenal, who is now the leading marksmen in the top section.
A 14th-minute cross by Andy Impey saw the Welshman soar above Leeds' acting captain, David Wetherall, but the Frenchman, Sammassi Abou, could not apply the touch to his knock-down that would have left Nigel Martyn helpless. The England goalkeeper then made a desperate reflex save to prevent Gunnar Halle conceding an own goal.
When Leeds did create an opening, shortly before half-time, Hasselbaink's free header from Bruno Ribeiro's centre was so wayward that it was impossible to imagine the spree he would later enjoy.
Leeds showed greater urgency after the interval. However, Wallace's attempt to win a penalty off Unsworth - with a dive out of the Greg Louganis manual - was symptomatic of their desperation.
It was no great surprise, therefore, when West Ham struck with a goal exemplary in its build-up and exquisite in execution. Tim Breacker lofted a long pass for Hartson to outjump Wetherall. Lampard beat Halle to the ball and angled a low, first-time shot beyond Martyn.
Lampard's father, who is now Redknapp's assistant, had famously scored West Ham's winner at Leeds to defeat Everton in an FA Cup semi-final 17 years ago. But history was not to repeat itself.
A fightback began after Steve Potts' foul on Hasselbaink. Haland and Lee Bowyer teed the ball up for the Dutchman to drive it through a crowded penalty area and into the net from 25 yards.
Suddenly, the fans found their voice and Leeds their form. Still they left it late: only four minutes remained when Haland rose like Jack Charlton of old to nod in Ribeiro's corner, the Norwegian's first goal for Leeds arriving on his 25th birthday. He had seldom been far from Eyal Berkovitch's side; significantly the Israeli had been substituted minutes earlier.
There was more to come. David Robertson, barracked for his error-strewn display, surged down the left in the final seconds before crossing for Hasselbaink to plant a sharp, downward header past Miklosko for his sixth goal of the season. The faithful were triumphant, but Graham will know there is still much work to be done.
Goals: Lampard (64) 0-1; Hasselbaink (76) 1-1; Haland (87) 2-1; Hasselbaink (90) 3-1.
Leeds United (4-4-2): Martyn; Halle, Wetherall, Radebe, Robertson; Kelly, Bowyer, Haland, Ribeiro; Hasselbaink, Wallace. Substitutes not used: Lilley, Harte, Maybury, Molenaar, Robinson (gk).
West Ham United (3-4-1-2): Miklosko; Potts, Pearce, Unsworth; Breacker, Lomas, Lampard, Impey; Berkovitch (Moncur, 84); Hartson, Abou (Dowie, 87). Substitutes not used: Rowland, Paulo Alves, Forrest (gk).
Referee: G Ashby (Worcester).
Booking: West Ham: Potts.
Man of the match: Haland.Reuse content