Plymouth Argyle Ladies are still ninth in the FA Women's Premier League Southern Division after a 2-1 loss at home to West Ham.
Gemma Shepherd's two goals in the first 15 minutes were enough for the London club, who are second in the table.
Argyle put the visitors under more pressure in the second half.
They were rewarded with a goal from striker Tash Knapman, who volleyed in Laura Perrett's cross in the third minute of stoppage time.
Knapman is the league's top scorer with 11 goals in 12 games, two ahead of West Ham's Shepherd.