Matildas captain Kerr, who looked to have been rediscovering her best form of late with five goals in her previous five games, had four opportunities in the opening 20 minutes to give Chelsea a flying start in the top-of-the-table clash in Kingston-Upon-Thames.

But despite her excellent movement allowing her to get a sight on goal, Kerr's finishing instincts deserted her, as they have sometimes done before in her Chelsea career, as she showed a lack of composure in front of goal.

Chelsea, though, ended up not ruing those misses as they earned the victory that sees the Blues overhaul the previously unbeaten United at the summit on goal difference, while also enjoying a game in hand.

Pernille Harder finally put Chelsea in front on the half-hour mark after all the champions' early pressure finally paid off but a magnificent individual goal from United substitute Lauren James levelled affairs on the hour.

But on song Kirby, who had scored four in her last game, gave Chelsea the win four minutes later, latching on to a long goalkeeping clearance before a calm finish.

And Kirby later had some words of consolation for her Australian strike partner after her difficult day.

"Sam's a great girl, not just a great footballer but a great person. We get a really good vibe off each other, and if I put the ball in the right areas, I know she's going to get on the end of them," the England international told BT Sport.

"She's a confidence player and we need to make sure we get around her and don't put too much pressure on her because there's obviously a lot of pressure on her coming in.

"Sam's a massive player for us and we have to make sure we keep her head in a good spot.

"But I'm really enjoying it (playing alongside Kerr) and hopefully we can keep building."

Elsewhere in the WSL, other Matildas went head to head as Hayley Raso's Everton beat Chloe Logarzo's Bristol City 4-0 while Alanna Kennedy's Tottenham beat Emily van Egmond's West Ham 1-0.

Kennedy and van Egmond have this month both signed permanent deals with their London teams after being on loan from US clubs but it was the Spurs midfielder left celebrating in the derby after Lucy Quinn's first-half winner.

Arsenal brought another Australian international Caitlin Foord off the bench for the last 20 minutes against Reading but the Gunners had to settle for a 1-1 draw that leaves them third, three points behind United and Chelsea.

Australian Associated Press