Howard Wilkinson has it all to do if he is to keep Sunderland in the Premiership as the Hammers hauled themselves off the bottom of the table.
The new manager made six changes to the side beaten at Arsenal that finally ended Peter Reid's seven-and-a-half year rein, including the return from injury of striker Kevin Phillips, but the performance was far from convincing.
There was no place, however, for £8million striker Tore Andre Flo, crowd pleaser Julio Arca or David Bellion and there was no denying the visitors deserved to win.
The crisp and inventive passing of Joe Cole and Paolo Di Canio had the Black Cats defence in disarray with the 22nd minute match-winning goal a cut above anything Sunderland could produce.
Michael Gray failed to cut out a stunning pass from Di Canio and Trevor Sinclair streaked clear to thump a 20-yard drive into the roof of the net to leave third choice goalkeeper Jurgen Macho well beaten.
Cole had two golden chances to increase the lead before half time with Sunderland relying on central defender Jody Craddock to come closest to an equaliser.
Bellion replaced a subdued Matt Piper after the break and the French teenager injected much-needed pace into the home side.
In the 51st minute David James failed to hold on to his fierce left-shot shot and although Phillips forced the loose ball home a linesman's flag cut short the celebrations.
Only a brave save by Macho denied the lively Sinclair in the 63rd minute after the winger had weaved his way past three defenders and Di Canio fared no better with a powerful shot that the keeper saved at the second attempt.
Niall Quinn, who replaced Marcus Stewart after an hour, hit the inside of the post with a delicate lob that rebounded into the grateful arms of James and another fierce drive from Bellion flashed just over the bar.
Wilkinson defended his decision to leave out record signing Flo, claiming the Norwegian still has a part to play. "Of course he has a future here,'' he said. "I don't think he is up to match pace.
"I don't know enough about the players but we had two practice matches and all I do know is I selected the best team. I would not be here if we did not have problems and there is plenty to work on.'' Hammers boss Glenn Roeder expressed delight that his side had climbed out of the relegation zone.
"That's the first time we've managed to get off the bottom and we've got to make sure we don't go back there again," he said.
"We've got our game in hand at Fulham on Wednesday and we can go there with confidence. Sunderland is a hard place to come and get a result, especially as we knew they would be trying to impress their new manager.''