Kevin Nolan and Carlton Cole were amongst the goals as West Ham strolled to a third consecutive away win, comfortably brushing past a stuttering Nottingham Forest 4-1.
The experienced duo, accomplished Premier League players over recent seasons, headed home in the first half after Forest captain Luke Chambers had put through his own goal.
The hosts hit back when substitute Joel Lynch fed Robbie Findley to reduce the deficit midway through second half, but Winston Reid's goal left manager Steve McClaren in no doubt about the huge task facing him at the City Ground when he tapped in a fourth for the Irons with 13 minutes remaining.
Findley got his head to Lewis McGugan's outswinging corner in the 12th minute but nodded wide of the upright, while the Hammers surged forward from the restart, Cole responding with a glancing header that went wide following Joey O'Brien's early cross.
Yet the Hammers were ahead in the 21st minute, Matt Taylor whipping the ball into the six-yard box, only for Chambers to fumble it into his own net.
Nolan used his head to double the advantage three minutes later, James Tomkins nodding the ball into a throng of visiting players for the former Newcastle midfielder to bag his second goal this term.
Forest had two opportunities to reduce the deficit almost immediately. Ishmael Miller sprang clear on the right wing but stubbed his shot into the side netting, before Rob Green denied McGugan following Chris Gunter's weighted cross.
But Allardyce's men heaped more misery on McClaren`s team in the 32nd minute, Cole nodding home Reid's pacey cross.
Andy Reid and Lynch combined to slot a ball across the box to Findley who eagerly slotted home to raise Forest hopes.
But the comeback was dead and buried in the 77th minute when Reid latched onto Taylor's pinpoint cross to slip the ball beyond Lee Camp.