Katie Swan became Britain's youngest ever Fed Cup player at the age of 16 as she beat South Africa's Ilze Hattingh.
The teenager, ranked 524th, won 6-3 6-0 to give Britain a 1-0 lead in their opening tie at the Europe/Africa Group 1 tournament in Eilat, Israel.
Heather Watson and the doubles team of Jocelyn Rae and Anna Smith will play the remaining matches in the best-of-three tie.
Whichever of the 3 countries tops their pool (B) after the round robin matches plays the winner of Pool D (Belgium, Bulgaria, Hungary & Latvia). The winner secures a World Group II play-off in April.