Rampant West Ham booked a first League Cup semi-final for 20 years after knocking holders Manchester United out of the Carling Cup at snowy Upton Park. Former Red Devil Jonathan Spector was in inspired form, scoring with a header and a close-range finish to notch his first goals in English football. The disjointed visitors, previously unbeaten this season, conceded again as Carlton Cole nodded in after the break. Cole then turned Jonny Evans to fire simply past Tomas Kuszczak. Though Manchester United manager Sir Alex Ferguson predictably did not select his strongest team, the starting XI could still boast the likes of Ryan Giggs, Darren Fletcher and Javier Hernandez. So it still registers as something of a shock that West Ham, bottom of the Premier League, ran out such convincing and deserved winners against the league leaders - especially in light of the Londoners' poor start to this season. And under-pressure Hammers boss Avram Grant may now insist they are over their bad patch after a performance that was rich in promise, both individually - Nigerian striker Victor Obinna was hugely impressive as he created all four goals - and collectively. The match started fast in freezing conditions, with both teams attacking each other as the play moved swiftly from end-to-end. West Ham could have suffered a dispiriting early deficit but for the heroics of England squad goalkeeper Robert Green, so maligned after his disastrous World Cup campaign. Only seven minutes had passed when Gabriel Obertan burst into space in the box to hammer a powerful low shot towards goal, but Green superbly pushed it onto the post before James Tomkins quickly hacked the ball away to safety. The visitors briefly appeared to take control, with French under-21 winger Obertan causing Julian Faubert problems as he narrowly failed to present Giggs with a simple opportunity to score. Though Radoslav Kovac smashed a decent chance over the bar, the Hammers appeared to be playing firmly on the back foot. Yet Spector took charge of the match in the 15th minute as he brilliantly rampaged through the heart of the visitors' half, with Anderson's failure to challenge allowing him to set up Obinna. The Nigerian's shot nestled in the net after an obvious deflection and Upton Park celebrated what they thought was a goal for a full minute. But, though it looked like the ball had come off United defender Chris Smalling, the referee rightly ruled that it had skimmed off Spector - and disallowed it because he was offside. Minutes later Spector, who made eight first-team appearances for United, gave West Ham the lead. A clever cross from Obinna was hung up perfectly over United's back-line and the American beat Fletcher to it and looped a well-placed header past Poland's Kuszczak. West Ham were now winning most of the individual battles and Spector added to the Londoners' advantage seven minutes before half-time. Once again slaloming through the opposition's sleepy midfield, Spector popped a sharp pass into the feet of Obinna, who controlled it well under a heavy but futile challenge from a slipping Fabio. Spector then sprinted to collect the loose ball before firing home emphatically from close range with both Smalling and Kuszczak unable to stop him. The visitors tried to respond and Bebe, playing on the right, had a header plucked just from underneath the bar while Green again had to avert danger from under his own bar as Fabio's cross deflected viciously off Luis Boa Morte. But West Ham had the best remaining chance of the first period, Obinna forcing a superb low stop from Kuszczak after Cole's knock-down. Ferguson brought on Federico Macheda for the largely ineffective Bebe for the second half, but it made little difference as United's display remained distinctly below the standards they usually set. Defensively they were especially lacking, and slack marking allowed Obinna to whip over a brilliant cross for Cole to nod a textbook header past Kuszczak for his 50th career goal. The excellent Obinna embarrassed Rafael da Silva, on for his brother Fabio, in the 66th minute with some impressive trickery down the left wing to create West Ham's third goal. His pass into the middle of the penalty area was controlled well by Cole, who turned Evans with remarkable ease before slotting a low shot home easily. With the snow falling ever heavier, the white match ball was replaced with an orange one before the humbled Evans was replaced by Wes Brown in defence. Giggs then failed to control Fletcher's clever through-ball when clear while Hernandez headed wide when well placed, summing up United's misery. Obinna even tried an ambitious free-kick from over 30 yards before the end, displaying the confidence coursing through the veins of a west Ham side which notched their biggest win over United in 80 years. Source: BBC