Chelsea survived a reading resurgence in the snow to end the year top of the table with a 3-2 victory at icy Kingsmeadow.
The Blues had raced into a three-goal lead in the first half but the Royals scored twice in a minute to set up a nervy last half-hour for the champions.
Emma Hayes’s side took the lead in the 16th minute when a quick free-kick saw Johanna Rytting Kaneryd play in Fran Kirby to slot into the bottom left corner, though the forward looked offside.
Jelena Cankovic then scored twice in five minutes to put the hosts 3-0 up.