Holders Manchester United were knocked out of the English League Cup after the Premier League leaders suffered a shock 4-0 loss away to bottom of the table West Ham at a snowy Upton Park on Tuesday.
United, who've won the trophy for the past two seasons, found themselves 2-0 down behind before half-time after USA international Jonathan Spector struck twice. 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
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 ten changes to the side that beat Rovers with only Anderson remaining. The boss, while unrepentant over his decision to field a youthful side, said: "We made a few errors on the goals and really you can't give away goals like that, even though they are young.
"We've always done well with young players coming through these periods. A few years ago we lost at Coventry and they learned a lesson that day," he went on. "Today, 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 almost found themselves a goal down when impressive Nigeria forward Victor Obinna, on loan to West Ham from Inter Milan, saw a deflected shot go in off Spector only for his strike to be ruled out for offside.
But minutes later the Hammers were ahead when Spector headed in from Obinna's chip. And the dominance of West Ham, who last weekend beat Wigan 3-1, was rewarded still further in the 37th minute when Fabio's attempted block fell into the path of Spector, who shot home from close range.
An error from England goalkeeper Robert Green, whose clearance hit the back of Federico Macheda, almost let United back into the match. However, the Hammers instead 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 ten minutes later for United's fourth.
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 clashes see a 'Second City' derby between Premier League pair Birmingham and Aston Villa while second-tier Ipswich are at home to top-flight West Bromwich Albion.