Chelsea dropped points at home for the first time in the Women's Super League (WSL) this season after West Ham's injury-time equaliser at Kingsmeadow on Sunday. Following Chelsea's midweek extertions in the Champions League, manager Sonia Bompastor made seven changes to the lineup that started against Manchester City on Thursday. Two of the new additions -- Maika Hamano and Aggie Beever-Jones -- put Chelsea 2-0 up early into the first half before Shekiera Martinez havled the deficit close to the break. West Ham pushed hard for an equaliser and got reward for their efforts in injury time when Martinez headed past Hannah Hampton for her second goal of the evening. West Ham are only the third team to take points off unbeaten-Chelsea this season, with Leicester City and Brighton also holding Bompastor's side to draws. The result keep leaders Chelsea six points clear of second-placed Arsenal, who beat lowly Crystal Palace 4-0 earlier on Sunday. Beth Mead bagged a brace for the north London side, with Alessia Russo continuing her fine goalscoring form with her 11th league goal of the season. Manchester United maintained pace at the top of the table with a 2-0 win over Everton while City bounced back from their midweek Champions League exit with a 2-1 win over Brighton. Elsewhere, Liverpool fell to a second succesive league defeat after a 2-1 loss at home to relegation-threatend Aston Villa while Tottenham were held to a 1-1 draw against Leicester.