The South African team will have to fight for all three points on Saturday, as they aim to claw their way back from 2-0 down after a tough first day of the Davis Cup by Rakuten World Group II tie against Bulgaria at the National Tennis Centre in Sofia on Friday.
Making his Davis Cup debut, Lleyton Cronje fell in a straight-sets defeat to the Bulgarian team's No 1 player, world No 162 Dimitar Kuzmanov, who earned a 6-3, 6-1 victory.
In the second singles match, the SA squad's top player, Philip Henning, went down to Alexandar Lazarov, with the Bulgarian No 2 racing to a 6-0, 6-1 win as the hosts took control of the tie.
"Today was unfortunately one of those days when you say it was a tough day at the office," said SA captain Christo van Rensburg.
"Lleyton and Philip ran into two guys today who are very familiar with playing on clay and it was actually an exhibition to see how well these guys were moving on the court."
South Africa still have a chance to win the fixture, with three matches scheduled for Saturday's second and final day of competition.
Cronje will pair up with experienced Davis Cup star Raven Klaasen, as they face Alexander Donski and Petr Kuzmanov in the doubles rubber.
In the reverse singles matches, Henning will meet Kuzmanov, and Cronje is up against Lazarov.
"We've discussed what lies ahead of us in the next matches tomorrow," Van Rensburg said.
"It's obviously going to be tough, and we have no room for error."