Julian Cash and Lloyd Glasspool avoided a huge scare to triumph in the doubles and put Great Britain into the final round of Davis Cup qualifying with a 4-0 win over Norway.
Wimbledon champions Cash and Glasspool were the heavy favourites against inexperienced duo Viktor Durasovic and Nicolai Budkov Kjaer, ranked 491st and 1,187th in doubles respectively.
The pair raced through the first set but completely lost their way in the second in an entertaining encounter in Oslo.
Cash and Glasspool then held firm to eventually come through 6-2 2-6 7-6 (7-5).
After Cash produced a service winner to secure victory, he started to walk back to the baseline, with all of the players thinking it was a 10-point match tie-break.
However, the umpire intervened to confirm Britain had wrapped up the best-of-five tie at the earliest opportunity.
“It means the world,” Glasspool said of securing a first Davis Cup match win.
“It was a little monkey on our back and now we can both free up a little and hopefully get many more wins.”
Jacob Fearnley later beat Budkov Kjaer 3-6 6-4 10-7 to make it a clean sweep for Great Britain.
The returning Jack Draper and Cameron Norrie beat Durasovic and Budkov Kjaer respectively in the singles on Thursday to put Leon Smith’s side in a strong position.
Draper did not play on Friday and he later withdrew from next week’s ATP tournament in Rotterdam, saying: “While I am feeling positive about how my recovery is going I have been advised not to rush straight out and potentially compete in back-to-back matches.
“As disappointed as I am not to be back out there, overall I am trending in the right direction.”
Britain will face either Ecuador or Australia later in the year for a place in November’s eight-team Finals.