Katie Boulter put in one of her best clay-court performances to beat Clara Burel and give Great Britain a 2-1 lead over France in their Billie Jean King Cup qualifying tie.
Boulter suffered a heavy defeat in her singles match on Friday but showed real grit to beat Burel 7-5 6-0.
The Briton had been a break down in the first set but reeled off nine games in a row to seal victory.
Emma Raducanu can wrap up the tie for GB if she beats Diane Parry.
The winner of the best-of-five tie advances to November's 12-team finals.