An evenly-poised game swung the Blues' way just before half-time when JLloyd Samuel was red-carded for hauling down Didier Drogba, and Frank Lampard converted the resultant penalty. Deco, Branislav Ivanovic and Drogba added further goals in the second half.
Liverpool's stuttering start to the season continues. Fernando Torres, scorer of the Merseysiders' opener against United last weekend, equalised Bobby Zamora's opener for Fulham at Craven Cottage, only for Erik Nevland and Clint Dempsey to ensure a shock win for the Cottagers. For good measure, Liverpool lost both Philipp Degen and Jamie Carragher to straight red cards.
In the day's early kick-off, Arsenal comfortably saw off Tottenham at the Emirates Stadium. Robin van Persie and Cesc Fabregas struck within a minute of each other before half-time, and the Dutchman added a second after the break.
Everton and Aston Villa did little to further their hopes of breaking into the top four, after fighting out a 1-1 draw at Goodison Park in which both sides were reduced to 10 men.
Further down the table, Sunderland came from two goals down to draw 2-2 with West Ham at the Stadium of Light, while Wolves did likewise to snatch an unlikely point at Stoke's Britannia Stadium.
Burnley's fine run of home form continued with a 2-0 win over troubled Hull City. Portsmouth remain bottom, but have far rosier prospects after thumping Wigan 4-0 at Fratton Park.