Bethesda coach Gerallt Hughes is entering the contest with mixed emotions. On one hand his club will host its biggest crowd in years but on the down side his young side will be up against one of the most consistent and proven sides in the cup.
"This is going to be the match of a lifetime for most of the players," explained a cautious Hughes. "The gods smiled on us when we got the draw as Cardiff is the capital of Wales and Cardiff RFC is the most famous rugby club in world rugby."
Bethesda rely heavily on local talent and actively encourage development within their own club. Full-back Gwyn Hughes and winger Martin Williams are only five games into their senior careers having coming through the youth system but will now face the biggest challenge of their careers.
"We've got three or four players who played youth rugby last season who are now in our senior squad so we are a young side. However we like to play an expansive game. We have a light pack and like to move the ball around at every opportunity. Sometimes it doesn't work but our strength is our unity.
Bethesda Chairman Huw Jones added, "On Saturday afternoon all the shops and all the pubs will be closed as everyone wants to see this match."
Flanker Rhys Shellard will lead Cardiff for the second time this season in a side which has a number of changes from the team that has beaten Pontypool and Cross Keys in the last fortnight. Only Ryan Howells retains his position in the starting line-up.
Returning to the team for only his second competitive game of the season is centre Richard Jones. He forms an experienced midfield alongside Shaun James and player-coach Lee Jarvis while Wales cap Craig Morgan returns on the left wing.
The pack has a more settled look with props Phil Osborne and Ian George the only changes from recent weeks.
Bethesda officials are describing the match as their biggest match since the club was founded 35 years ago.
Cardiff team manager Gafyn Cooper said, "This is what the cup is all about. It takes us out of our normal environment and to places where clubs haven't been before. It adds an extra interest to the competition. We also know we face a tough task on Saturday as we are well aware that Bethesda are unbeaten in their league this season."
Cardiff: Roger Davies; Ryan Howells, Shaun James, Richard Jones, Craig Morgan; Lee Jarvis, Garyn Lucas; Ian George, Garry Horrigan, Phil Osborne, Matthew Veater, James Down, Adam Powell, Craig Everett, Rhys Shellard (capt)
Replacements: Matthew Howells, Richard Cornock, Lewis Mills, Rhys James, David Walsh, Gareth Davies, Gareth Chapman.