Unheralded British youngster Kyle Edmund faces a Davis Cup baptism of fire when he makes his debut in the final on Friday against Belgium's David Goffin in the opening rubber.
The 20-year-old, ranked just 100th in the world, will join an elite group, including Pete Sampras, to make their debuts in the final of the team event that Britain have not won since the days of Fred Perry in 1936.
The last time Britain reached the final in 1978, John McEnroe played his first Davis Cup singles rubber for their U.S. opponents.
The visiting team's talisman, world number two Andy Murray, will face Ruben Bemelmans in the second rubber of the best-of-five contest on a drop-in claycourt at the 13,000-capacity Flanders Expo.
Edmund, who was playing claycourt Challenger events in South America until last week, was picked by captain Leon Smith ahead of the more experienced James Ward.
Belgium captain Johan Van Herck, spearheading their bid to win the Cup for the first time, also caused surprise by selecting world number 108 Bemelmans ahead of 84th-ranked Steve Darcis to face Murray on the opening day.
Saturday's doubles will see Andy Murray and older brother Jamie take on Darcis and Kimmer Coppelmans.
The make-up of the reverse singles, which will see world number 16 Goffin play Murray, could be changed, with Darcis and Ward potentially coming in to contest a decisive fifth rubber.
Edmund's selection was not unexpected after his results on clay in recent weeks but it will be a huge step up as he looks to become the first debutant to win a live rubber in the Davis Cup final.
"This will be the biggest crowd I've ever played in front of, it's a new experience for me," Edmund, looking calm and composed in a packed news conference, told reporters.
"It's exciting to play my first match for my country. At the same time, I've got a job to do which will be to give my best and put a point on the board for GB."
Captain Smith said it had been a "hard decision" but he had been swayed by Edmund's ranking and form on clay.
With Murray, who has provided eight of Britain's nine points on the way to the final, expected to win both his singles matches, Belgium are underdogs.
But Van Herck, leading Belgium's only appearance in a final since their defeat by Britain in 1904, believes the tie will go all the way and says the crowd will be like an extra player for the home side.