Nick Cushing’s side left it late to clinch all three points as a deflected Steph Houghton free-kick four minutes from time separated the sides, after Eniola Aluko had cancelled out Toni Duggan’s opener.
The triumph - the Club’s fourth in succession - condemned Chelsea to their first defeat on home soil in two years, and lifted City’s points total to 14 with a game in hand over those above them.
Skipper Houghton was delighted with the victory, asserting she is claiming the winner and insisting her side must believe they can go on to secure the title.
In her post-match interview, she reflected: “In the first half of the season, we had a few key players missing but credit to the squad - they dug out some results - and now, we’ve all come together since the World Cup and gelled really well.
“We’re really hungry and confident in our ability both individually and as a team. We’re still learning every single week and to come to Chelsea and win as we have done is brilliant - we should be really proud of ourselves.
“We knew it was going to be a tough game. Chelsea have been in form of late. We played really well against them at home and I thought we had been unfortunate not to come away with a win so today, the main objective was to do so and thankfully, we did.”
In arguably the Club’s best result of the season, City ground out this victory. After taking the lead on 12 minutes, the visitors let it slip by conceding just after the break but enjoyed a stroke of luck in the dying minutes.
It came in stark contrast to the same fixture last season in which Chelsea benefited from late good fortune to snatch the win at the death. This time, it was City’s turn.
After the home side’s 4-0 defeat at Sunderland last weekend had blown the title race wide open, Cushing’s side knew a victory in Staines would put them in the mix at the top.
In that knowledge, the Blues boss named an unchanged side to the one that defeated Doncaster 3-0 in midweek as City sought to extend their winning streak.
Buoyed by their three successive victories and impressive performances, the away side controlled the ball well in the opening 45 minutes. With precious points at stake, there were plenty of strong tackles flying in but City coped with the physical side of the game.
The visitors enjoyed the majority of possession, limiting Chelsea to half-chances and crucially they took their best chance when it arrived.
New signing Daphne Corboz, who scored at Bristol last weekend and set up Nikita Parris in Thursday’s win over Doncaster, was involved and showed once again exactly why Cushing was so pleased to capture her signature, floating the ball over the top to Duggan.
With the striker in red-hot form of late, there would only be one outcome as she controlled well before side-footing into the back of the net for her fifth goal in four games.
There was little in terms of goalmouth action from then on as Chelsea were restricted to half-chances and City headed into the break with their slender lead and hoping for a similar second half.
However, with their half-time team talk fresh in their minds, the home side looked much more lively after the restart and found an equaliser within three minutes, as Aluko was given too much time and space to drive forward before firing the ball beyond FA Women’s Cup semi-final between the two sides – attempted a chest-and-volley which lacked the power to trouble Bardsley.
That proved to be Chelsea’s best chance to turn the game on its head and they were punished for spurning it as the away side snatched all three points late on.
Christiansen was fouled just outside the box and Houghton stepped up for her third free-kick attempt of the evening, which took a wicked deflection of Claire Rafferty’s head and sailed into the back of the net.
The celebrations that ensued were understandable, heralding the sheer importance of the strike. Now, City just needed to hang on.
Parris then almost sealed the win in injury time, unleashing a powerful effort to the near post which Hedvig Lindahl did well to push wide - but fortunately, that proved to be the last attack of the game for either side and the visitors emerged victorious.
Next up for the Blues is a Continental Cup clash at home to Durham Women on Wednesday night (7pm).
Tickets are available and ticket information can be found here.
