Catarina Macario marked her first WSL start of the season with an early goal
Chelsea strengthened their position at the top of the Women's Super League table as they cruised to victory over West Ham at the Chigwell Construction Stadium.
Catarina Macario, Erin Cuthbert, Aggie Beever-Jones and Sandy Baltimore all fired superb efforts past hapless West Ham goalkeeper Kinga Szemik before Amber Tysiak turned into her own net late on as the Blues recorded their joint-biggest away win since September.
Macario opened the scoring when the ball fell to her just inside the penalty area, latching on to it with a side-footed volley over Szemik.
Cuthbert got the Blues' second with a drilled effort from outside the penalty area, with Beever-Jones emulating that goal with one of her own from a similar distance that crashed in off the far post before half-time.
French international Baltimore made it four shortly after the restart and Tysiak inadvertently turned into her own net late on.
The Blues sit seven points clear of second-place Arsenal before their meeting next weekend. Manchester City missed the chance to overtake the Gunners and cut the gap to the leaders after losing to Manchester United on Sunday evening.
West Ham, this their heaviest defeat of the season, remain 10th, three points clear of bottom side Crystal Palace.
Bompastor flexes attacking options
Erin Cuthbert and Aggie Beever-Jones both scored in the first half
Chelsea manager Sonia Bompastor opted to make five changes to her team from the side that drew 1-1 at strugglers Leicester City before Christmas.
Leaving Guro Reiten and Johanna Rytting Kaneryd, who had scored 10 of the Blues' 30 WSL goals between them this season, on the bench would have been seen as a gamble by some. Those who did start allayed question marks almost instantly, flexing the array of attacking talent Chelsea have in their squad.
The first four goals showed touches of class. An expert finish from Macario, on her first WSL start of the season, set a tone for what was to come and by the break, strikes from identical distances from Cuthbert and Beever-Jones put the sword to Rehanne Skinner's Hammers.
Any hopes of a second-half fightback were quickly ended when Baltimore fired in from distance. Tysiak's inadvertent own goal was a further blow to West Ham's impressive form at home this season.
Goal four signalled the changes from Bompastor with another London derby against title hopefuls Arsenal to come in a week's time. The Blues' French manager has utilised her star-studded squad perfectly so far, cruising in the league and yet to taste defeat since replacing Emma Hayes last summer.
There were very few signs of the pre-Christmas blip against Leicester City. In this form, even if Chelsea's title rivals keep putting pressure on them, it would take an almighty decline to see them not win a sixth consecutive WSL title come May.
Player of the match
After the opportunity to rate players has closed, the score displayed represents the average from all the submissions by BBC Sport users.
