West Ham knock out United in League Cup shock

United, who've won the trophy for the past two seasons, found themselves 2-0 down behind before half-time after Jonathan Spector, a former Old Trafford trainee, struck twice.

West Ham's Nigerian striker Victor Obinna (L) vies with Manchester United's Irish defender John O'Shea (R) during their quarter final League Cup football match at Upton Park, London. AFP

And another double, from England striker Carlton Cole midway through the second-half, sealed victory for the Hammers.

In Tuesday's other quarter-final, also an all top-flight clash, Arsenal beat Wigan 2-0 across London at the Emirates Stadium thanks to an Antolin Alcaraz own-goal and a second-half effort from forward Nicklas Bendtner.

United States defender Spector had never scored before during his six seasons in English football yet before 40 minutes were on the clock he'd netted twice against the holders, who came into this match on the back of a 7-1 league thrashing of Blackburn Rovers.

Sir Alex Ferguson, the United manager, made 10 changes to the side that beat Rovers, with only Anderson remaining.

Ferguson, while unrepentant over his decision to field a youthful side, told Sky Sports: "We made a few errors on the goals and really you can't give away goals like that, even though they are young.

"Today (Tuesday), West Ham approached it more like a cup tie, got stuck in and a lot of late challenges, things like that. It got the crowd up for them, but the error of the game was about the goals we gave away anyway."

Under pressure West Ham boss Avram Grant, asked if this result combined with last weekend's 3-1 league win over Wigan marked a turning point for the east London side, said: "I hope so but we have been continuing our process of developing our quality football.

"It's a new team with many new players and each game we are better. I hope to continue winning," the Israeli added.

United found themselves a goal down in the 22nd minute when impressive Nigeria forward Victor Obinna, on loan to West Ham from Inter Milan, saw his chip headed in by Spector.

And West Ham's dominance received fresh reward was rewarded in the 37th minute when Fabio's attempted block fell into the path of Spector, who shot home from close range.

The Hammers went further ahead when the in-form Obinna's excellent cross was headed in by Cole in the 56th minute before the same duo combined 10 minutes later for West Ham's fourth goal.

Arsenal's hopes of winning a first major trophy since 2005 appeared to have received a massive boost with United's exit but manager Arsene Wenger was taking nothing for granted.

"You have seen it in the Premier League, and tonight (Tuesday) with West Ham, it can happen to Manchester United, to Chelsea and to us this season.

"We have to accept there are no guarantees, even if we are in the semi-finals, that we will win the trophy," the Frenchman added.

"You cannot say that (winning a trophy) is not important, but we should also not make an obsession of that.

"The major trophies are the Champions League and the (domestic) championship, but if we can win this as well, we will take it."

Arsenal missed several chances before going ahead three minutes before half-time when Wigan captain Alcaraz put a Theo Walcott corner into his own net under pressure from Bendtner.

Denmark striker Bendtner sealed Arsenal's victory in the 67th minute when he turned in a low cross from Carlos Vela.

Defeat for Wigan was made worse by the loss of striker Victor Moses with a wrist injury.

Wednesday's last eight ties see a derby between Premier League pair Birmingham and Aston Villa while second-tier Ipswich are at home to top-flight West Bromwich Albion.