The excellently crafted goal came in the 23rd minute when Kerr controlled Lauren James’ long pass forward on her chest and sent the ball over Mary Earps and into the net.
United were left frustrated at no penalty being given after Nikita Parris went down under the attention of Kadeisha Buchanan around 10 minutes later, and team-mate Ona Batlle also had spot-kick appeals waved away.
The result of the crunch clash sees Emma Hayes’ Blues go two points clear of Marc Skinner’s United at the summit, with a game in hand.
Third-placed Manchester City are level on points with United after they won 2-1 at Brighton courtesy of a late goal from the league’s top scorer Khadija Shaw.
Shaw also opened the scoring with a 21st-minute effort that was cancelled out by Elisabeth Terland just after the half-hour mark.
The Jamaica forward then wrapped up all three points for Gareth Taylor’s team with a strike with a minute of normal time to go, her 15th league goal of the season. City, like Chelsea, are on a 13-match unbeaten run in the league.
— Man City Women (@ManCityWomen) March 12, 2023
Bottom side Leicester are a point behind 11th-placed Brighton, having played a game more, after they drew 0-0 at home with Everton.
A point and a place ahead of Brighton are Tottenham, who suffered their ninth successive WSL defeat as they went down 2-1 at Liverpool.
Spurs led early on through Rosella Ayane but Emma Koivisto equalised soon after and then set up Missy Bo Kearns for what proved the winner in the 35th minute.
Liverpool are now seven points clear of the relegation place.
A HUGE three points at Prenton Park ❤️
UP THE REDS! pic.twitter.com/H9fHdoDagn
— Liverpool FC Women (@LiverpoolFCW) March 12, 2023
England internationals Rachel Daly and Jordan Nobbs were on the scoresheet for fifth-placed Aston Villa as they won 2-1 at West Ham.
Daly netted her 11th league goal of the campaign in the first half and Nobbs extended the lead just past the hour mark before the home side replied through Viviane Asseyi.