West Ham, with Paolo di Canio in irrepressible form, proved far too strong for Charlton and unless their near neighbours wise up fast they could be heading for the big fall. Their manager, Alan Curbishley knows it and lambasted his normally resolute team afterwards.
For Harry Redknapp and the Upton Park faithful, however, this was a day of pure joy. West Ham's forwards took turns to wear the party hats but, almost inevitably, Di Canio donned the most colourful of all - though he only just shaded the artful Frederic Kanoute, who scored twice.
The Italian set the tone after 12 minutes with a wondrous backheeled goal which went in off a Charlton defender. After that the party rolled, with a supine Charlton offering little apart from Claus Jensen's midfield endeavours.
It was Charlton's heaviest defeat of the campaign, extending their dismal away run to six defeats. "Anything you want to say about my team today, you can write it and put my name to it," Curbishley said.
Charlton played into the hands of Di Canio, Kanoute and, less frequently, the home debutante Titi Camara. And Trevor Sinclair provided the best shot of the game, a 25-yard volley that cannoned in off a post for the fourth goal.
The damage had been done much earlier, Di Canio's audacious goal being followed six minutes later by the most eyecatching move of the game. Sinclair delivered a long-range backheel from the touchline that set Kanoute free to play the ball off Mark Kinsella as though he was a wall before driving with the outside of his right foot past the bewildered Dean Kiely.
Di Canio set up a routine third goal by outmanoeuvring two defenders to deliver a cross to the far post where Frank Lampard chipped in. Charlton's Richard Rufus and Jonatan Johansson then spurned wonderful chances before Michael Carrick's intelligent throughball sent Kanoute through for a simple fifth goal six minutes from time.
Afterwards, Redknapp indicated that his transfer activity was not over when he confirmed that an exchange deal involving his captain Steve Lomas and Rangers' Italian defender Lorenzo Amoruso was still a possibility.
West Ham: Hislop, Stuart Pearce, Song, Sinclair (Moncur 80), Winterburn, Lomas, Carrick, Lampard, Di Canio (Tihinen 86), Kanoute, Camara (Cole 80). Subs Not Used: Forrest, Diawara. Booked: Lomas. Goals: Di Canio 13, Kanoute 18, 84, Lampard 45, Sinclair 71.
Charlton: Kiely, Kishishev (Parker 70), Powell, Stuart, Rufus, Kinsella, Robinson (Konchesky 82), Brown, Jensen, Johansson, Svensson (Pringle 26). Subs Not Used: Caig, Todd.
Referee: S Dunn (Bristol).
