Cameron Norrie survived a scare against world number 545 Tomasz Berkieta to give Great Britain a 1-0 lead over Poland in the Davis Cup.
World number 34 Norrie saved set points in a nervy first set but recovered to win his nation's opening World Group 1 match 7-6 (11-9) 6-4 in Gdynia, Poland.
World number 227 Arthur Fery, 23, will make his Davis Cup debut in the second match against Olaf Pieczkowski, ranked 484, after British number three Jacob Fearnley pulled out with a rib injury.
The overall winners of the tie, taking place on Friday and Saturday, will play in next February's first round, and therefore have a shot at winning the title in 2026.
The world's number one doubles pair, Lloyd Glasspool and Julian Cash, will make their debut in Saturday's doubles, which will be followed by two reverse singles.
World number seven Jack Draper was unavailable for the tie because of an arm injury which has ruled him out of the remainder of the season.