All Whites defender Winston Reid scored a crucial winner for West Ham as they defeated local rivals Millwall 2-1.
Reid hit a stunning strike from just outside the penalty box, after Millwall keeper David Forde's weak punch in the 69th minute.
Liam Trotter had equalised for Millwall just three minutes earlier, after Carlton Cole had given the English Championship (second tier) front-runners the lead just on halftime.
West Ham now sit four points clear at the top, with 23-year-old Reid now established as a regular in the first team at Upton Park.
He has made 20 appearances so far this campaign, forcing his way back into the starting XI after dislocating his shoulder in November.
Hammers manager Sam Allardyce described the victory over Millwall as the best of his career.
The game was an early afternoon kick-off, due to a history of violent confrontations between opposing supporters.
Reid's West Ham travel to Peterborough next weekend, as they look to continue their push to retain top-flight status.
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