The only outfield change to the City side that narrowly lost to Everton two weeks ago saw Georgia Brougham come into the back three in place of the injured Abbie McManus, with Ashleigh Plumptre taking the captain’s armband.
Goalkeeper Demi Lambourne was also fit enough to re-take her place between the sticks after missing the trip to the Toffees, but she could do nothing to stop a stunning start from the away side.
Emma Hayes’ charges took the lead after just three minutes when Guro Reiten curled a free-kick straight into the top corner with her left-foot, after being felled by Esmee De Graaf 25 yards from goal.
Sam Kerr got in on the act just two minutes later, running onto captain Millie Bright’s pinpoint through ball to get one-on-one with the returning Lambourne, who initially made a strong save before the Australian international tucked home the rebound.
Despite her best efforts, the shot-stopper was beaten again on seven minutes. England exchanged a one-two with Kerr, before hammering the ball into the roof of the net.
That emphatic finish was followed by a fourth on 12 minutes. England turned provider as Reiten’s corner was met by the Lioness, who flicked it on to Aniek Nouwen for a simple, close-range finish.
Leicester managed to fashion their first real opportunity midway through the half thanks to a neat cross-field pass from De Graaf across to Freya Gregory, who drove into the box but could only find the side netting.
The away team continued to search for more goals when the ball fell kindly for Erin Cuthbert, though the Scotland midfielder fired wide of the target.
Chelsea would not have to wait long for their fifth of the afternoon, however. Reiten claimed the assist this time, standing up the cross for England to head in at the back post to double her own tally ahead of the half-hour mark.
Plumptre took a knock to the head trying to prevent the ball crossing the line and had to be substituted, replaced by Sophie Barker, as the Blues kept up their relentless pursuit of further goals.
Lambourne was called into action twice more, saving Bright’s effort at her near post when Niamh Charles slipped the centre back in, before also claiming Kerr’s header from Reiten’s latest dangerous cross.
Bright went close again, heading wide from Cuthbert’s corner, prior to Reiten notching her brace in first-half stoppage time. Ji So-Yun slipped the ball through to the winger, who chipped it into the far corner for Chelsea’s sixth.
Less than two minutes into the second period, Kerr headed in a seventh goal, rising to meet England’s cross.
Jess Carter’s ball into the box was soon taken on the volley by Charles, diverting it wide, while Reiten, on a hat-trick, headed past the post from Kerr’s deep cross.
A double Foxes change saw youngsters Elysia Boddy and Monique Robinson enter the fray for Shannon O’Brien and Molly Pike, the latter forced off through injury. Academy player Robinson was making her WSL bow, while it was also 18-year-old Boddy’s first appearance at King Power Stadium.
Drew Spence then saw a powerful strike beaten away by Lambourne, ahead of Cuthbert’s corner grazing the top of the crossbar.
A Chelsea substitute scored their eighth in the 88th minute as Lauren James was able to find the target with a first-time finish from Charles’ cut-back.
And the ninth goal arrived in the final minute of normal time. Kerr, James and Spence were all involved before the latter's clever flick found Fleming to toe-poke the ball into the back of the net.
Natasha Flint almost netted a consolation for the Foxes in added time but couldn’t quite find the finishing touch to Boddy’s through ball.
Major moment…
Chelsea were at their ruthless best scoring four times inside the opening 12 minutes. It was a series of killer blows for the home side and they were unable to recover from that.
Where do we stand?
City sit 11th in the Barclays FA Women’s Super League, remaining on 12 points from their 18 matches in the division.
Coming up…
Leicester host Arsenal at King Power Stadium in the Barclays FA Women’s Super League next Sunday (12:30pm BST kick-off).
The details…
City: Lambourne; Howard, Brougham, Plumptre (C) (Barker 31’); De Graaf, Tierney, Pike (Robinson 79’), Purfield; O’Brien (Boddy 79’), Flint, Gregory.
Subs not used: Harris, Goodwin, Bailey-Gayle.