Katie Swan became Britain’s youngest 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.
Britain must win three ties to secure a World Group II play-off in April.
Captain Judy Murray selected Swan to play singles after Australian Open semi-finalist and British number one Johanna Konta withdrew because of illness.
Swan, who reached the Australian Open junior final last year, was ranked 126 places higher than 19-year-old Hattingh and beat her in just 55 minutes.
“I was really excited to play but I was also a bit nervous, which was showing in the beginning, but I managed to relax after a few games and I started playing really well,” Swan told the Fed Cup website.
“It’s just amazing to get to play for your country – for me it’s the best thing in tennis representing your country.
“British tennis is doing amazing, we have the Davis Cup boys who just won and obviously Jo and Andy (Murray) and Jamie (Murray) doing so well in Australia. It’s inspired the whole team.”
Watson, ranked 85th, can seal victory in the tie if she beats world number 317 Chanel Simmonds in the second singles, which is currently being played.