Emily Scarratt's late penalty saw England beat France 20-18 to maintain their 100% record and move top of the Women's Rugby Super Series table.
After wins over USA and Canada, England started badly when Cyrielle Banet touched down after just over a minute.
Kelly Smith's try got England back in it but Caroline Boujard's try helped France to an 18-5 half-time lead.
Scarratt scored two tries and with eight minutes left, her penalty secured a lead for the first time - and a win.
After the victory in San Diego, England are thre points clear of New Zealand, who they play in their final game of the Series on Sunday.
A win would ensure Simon Middleton's team officially become the world's best side.
Reacting to his side's ninth win in 2019, Middleton said: "We showed the character in our team to come back from a tough position. We knew we could as we've got a lot of belief in being able to close games out - we did it against Canada and we've done it again today with some monumental efforts on the field.
"Scarratt is a bit special isn't she? There is nothing she cannot do really.
"New Zealand will be hurting from their defeat against France. They're world champions and it's always going to be a tough game when you play against them. We're going to have to regroup and dust ourselves down, but one thing we won't be short of is spirit."