Hammers got back to winning ways and ended their run of six away games without a win as they secured an impressive 2-0 victory at Nottingham Forest.
Goals from Marlon Harewood and Jermain Defoe at either end of an entertaining 90 minutes helped Alan Pardew's men to bounce back immediately from their disappointing Boxing Day defeat against Ipswich Town and get their promotion hopes back on track.
The Hammers boss had made just one change following defeat against the Tractor Boys, bringing in Robbie Stockdale at right-back to allow Hayden Mullins to push further forward into a more familiar central midfield role at the expense of Kevin Horlock.
Harewood, who had passed a late fitness test after picking up a slight knock on Friday, continued in his attacking position on the right up alongside Jermain Defoe and David Connolly, and his inclusion was fully justified seven minutes in.
In Hammers' first real attack of the game, Matt Etherington raced down the left before sending over an inviting cross that was flicked on by Defoe into the six-yard box, where Harewood arrived late to slot the ball past goalkeeper Darren Ward and silence the jeers of the home crowd.
It was the big striker's fourth goal in eight games since arriving at Upton Park and his 16th of the season - reminding Forest fans of just exactly what they have missed following his departure.
The hosts responded to their early blow well, though, and came close to equalising soon after Harewood's strike. David James had to be alert to dive at the feet of striker Marlon King in the ninth minute, while Gareth Taylor blasted over from a good position just two minutes later.
However, Hammers always looked threatening and Harewood almost returned a favour for Defoe when he cut the ball back for the young striker to fire in a blistering shot that was beaten away by Ward.
The Forest stopper was called into action again on the half hour mark, when Wayne Quinn's cross was only cleared as far as Mullins, whose stunning volley was superbly blocked by Ward.
Quinn's slip nine minutes later almost proved costly as King gained possession but the striker shot wide and Hammers went into the break holding a relatively comfortable lead.
Forest unsurprisingly came out for the second half in more determined mood but, apart from a couple of Taylor headers and an Andy Reid free-kick that sailed just over the bar, David James and his defence were rarely troubled by their opponents.
In fact, it was Hammers who looked most likely to find the net, and the lead should really have been doubled in the 67th minute, when Connolly skipped away from a couple of defenders but, rather than pick out the perfectly positioned Harewood, chose to shoot himself and saw the effort tipped over by Ward.
Connolly was then replaced by Horlock as Pardew sought to tighten up his midfield and hold on for the win, but his troops were in no mood to settle for a simple 1-0 win. Defoe went close twice with low shots inside the area, while Mullins was again denied his first Hammers goal by an excellent save from Ward.
The killer second finally arrived six minutes from time, when a simple long clearance from Tomas Repka - once again excellent in the heart of the Hammers defence - dropped in behind the Forest backline and was collected by Defoe, who raced into the area before turning inside his England under-21 colleague Michael Dawson and curling a superb shot beyond the reach of Ward.
That extinguished any possible hopes of a Forest comeback and Hammers were content to keep possession in their own half as the clock wore down, although Etherington should have added a third in the dying moments when he latched on to Defoe's low cross and poked the ball towards an empty net but Dawson somehow got back to clear off the line.
That miss was soon forgotten as the final whistle blew, and Hammers were left to celebrate their first away win since October 4. Now up to fifth, league matters will be put to one side as Pardew and his team prepare for an FA Cup third round tie at Wigan next week, but the Hammers boss will simply be delighted that his players have bounced back from the Boxing Day disappointment and ended 2003 on a high.
By Danny Francis