The Hammers arrived in West London on the back of just one victory in 10 games, and boss Gianfranco Zola, who had spent seven years of his playing career with the Blues, was under pressure to earn a result at his former home.
Chelsea manager Luiz Felipe Scolari recalled midfielder Frank Lampard for the fixture with his former club, but he opted to leave out striker Didier Drogba, who was returning from injury. Zola decided to make three alterations to the team that started their in 2-0 defeat to Tottenham Hotspur.
The home side began the game well, with Michael Ballack being at the centre of the majority of their play. The German midfielder sent a stinging drive over the crossbar, before just failing to find Joe Cole with a precise pass that had split the Hammers' defence.
Chelsea continued to have the better of the opening exchanges but they couldn't net the early goal that their play deserved, with Alex heading wide after being found by Lampard's free kick.
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West Ham were very much on the back foot, but they stunned Stamford Bridge by taking the lead on 32 minutes through Craig Bellamy, who controlled Mark Noble's pass before driving a half-volley past Petr Cech.
Chelsea's frustration began to grow as Ballack and Ashley Cole were booked in quick succession, and although they continued to press for an equaliser before half time, they were unable to create any clear opportunities.
However, immediately after Anelka's equaliser, Carlton Cole wasted two fantastic chances to regain the lead for the Hammers. After missing from six yards, the former Chelsea man fizzed an attempt marginally wide of Cech's post.
Chelsea began to surge forward with the incentive of top spot inspiring their players to push West Ham back, with Lampard forcing Green into a superb save from distance as the clock reached 70 minutes.
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Green was beginning to act as a one-man defence for West Ham as Chelsea continued to up the tempo, and after tipping Drogba's volley away for a corner, the English stopper did well to claim Deco's deflected effort.
Salomon Kalou was the next to test Green, but again, West Ham's goalkeeper was equal to it, and he made his most timely intervention of the match with 10 minutes remaining to keep out Alex's header from close range.
That was the last of the clear-cut openings for the home side as West Ham held on for what was a morale-boosting point against their London rivals.
The Hammers used the result to turn their form around as they won four of their next six fixtures, and they continued to hover around the mid-table positions in the Premier League to end the season in ninth place.
As for Chelsea, just three wins in eight matches saw Scolari removed from his position in the dugout in February, but the Blues recovered to finish the campaign in third position to earn a place in the Champions League.