Eniola Aluko's second-half goal was enough for Chelsea to beat champions Liverpool as last season's top two met for the first time this year.
After a goalless first half, England striker Aluko put the hosts ahead by lobbing Reds goalkeeper Libby Stout.
Liverpool midfielder Fara Williams then had the chance to level from the penalty spot, but fired wide.
Her miss proved costly as Chelsea held on to secure their third league win out of three this season.
The Blues remain the only WSL 1 side to have a 100% winning record so far.
Liverpool, who beat Chelsea to last season's league title on goal difference, have now lost two of their first three league games.
Reds' boss Matt Beard, up against his former club, saw his side have most of the possession in a first half with few clear-cut chances.
Aluko had arguably the best opening of the first 45 minutes but, after bursting into the penalty area, dragged her right-footed shot wide.
At the other end, Gemma Bonner met Williams' cross at the far post, but headed over.
After the break, Aluko showed blistering pace to race onto Laura Coombs' ball and then calmly flicked a cheeky lob over goalkeeper Stout.
The visitors almost levelled moments later, but Asisat Oshoala blasted over from inside the penalty area.
Liverpool captain Williams was then presented with a chance to equalise, after the referee spotted a handball in the area, but she sent her penalty wide as Chelsea maintained an impressive defensive record which has seen them concede just once in their first three league games of 2015.
Chelsea: Lindahl, Blundell, Bright, Flaherty (capt), Fahey, Davison, Aluko, So-Yun, Rafferty, Coombs, Spence.
Substitutes: Hourihan, Groenen, Borges, Chapman, Brett, Meiwald, Banusic.
Liverpool: Stout, Harris, Easton, Bonner (capt), Murray, Schroder, Williams, Oshoala, Longhurst, Smorsgard, Dowie.
Substitutes: Gibbons, Ryland, Staniforth, Zelem.
Referee: Constantine Hatzidakis