Andre Ayew opened his West Ham account by scoring against his former club as they piled further pressure on Swansea City manager Bob Bradley with a 4-1 Premier League win at the Liberty Stadium.
Ayew, who traded south Wales for east London in August, had failed to find the net in 10 games for West Ham going into Monday's meeting.
But he ended his wait at his old stomping ground on Boxing Day, a simple close-range finish after Lukasz Fabianski had inexplicably parried an Andy Carroll header into his path giving West Ham a 13th-minute lead.
West Ham were in control throughout the first half and five minutes into the second period they made it 2-0 as Winston Reid headed home at the near post from a corner.