On an emotional day at Stamford Bridge -- which had become 'Samford Bridge' for one final Saturday -- the Matildas skipper hammered home a fabulous volley in the 34th minute, her 116th goal for the club to match the all-time record of her former strike partner Fran Kirby.
She even had her chances to break the record, blazing one over in the 89th minute of Chelsea's 1-0 win, before coming off to a standing ovation all around the ground in stoppage time -- even from United fans and players -- as everyone saluted her 158th and final match for the Blues.
It marked a fitting end to the 32-year-old's stellar six-and-a-half year career for the London giants, having won five Women's Super League titles there, three FA Cups and three League Cups, as well as twice being crowned golden boot winner as the WSL top scorer.
"It was an amazing day, kind of fitting to play against Man United, a team I've scored so many of my favourite goals against, -- and to score one like that today was awesome," said Kerr, who's expected to soon announce she'll be continuing her career in the US.
"I just wanted to come out here and have fun like I always do, but it's also fitting I end with Fran after we played some pretty good football together. But I mean, every goal to me for this club is special, I enjoyed every minute today.
"It's just, honestly, the biggest honour to play for this club, and I have so many amazing memories which I'll carry with me for ever."
She appeared with her one-year-old son Jagger in front of the cheering fans. "He's born in Chelsea, so it's kind of cute, and a nice little finish, but it was special to walk out with him and have my family here. A really sad day, but happy day, I guess," she smiled.
"It's going to be hard to leave, but I've only good things to say about the club and the people here."
Her send-off goal, an instinctive and deadly first-time effort lashed in at the near post from a Lauren James cross, was enough to earn the victory that ensured Chelsea finished third in the table, enough to earn them a place in the Champions League qualifiers next season.
They finished behind Arsenal, who sealed second place with their 3-1 win at Liverpool, and champions Manchester City, who won 4-1 at West Ham, for whom another favourite Matilda, Katrina Gorry, played her final game.
