Tom Wade has led Spartans to the third round for the first time since 2008-09.
Coverage: Live commentary on BBC Radio 5 Live, BBC Newcastle and BBC WM.
Manager Tom Wade says Blyth Spartans have an "outside chance" of continuing their giant-killing run against Championship side Birmingham.
Wade's side, who play in the Northern Premier League, have home advantage against Gary Rowett's team on Saturday.
Spartans have beaten Conference side Altrincham and League Two Hartlepool en route to round three.
"We need Birmingham to have a bad day and us to be absolutely superb," Wade told BBC Newcastle.
"We played Altrincham at home, I know they're not a Championship side but they're a good Conference side, nobody gave us any chance at all and we battered them.
"If we can put that kind of game on this Saturday, Birmingham have a bit of an off day, we carry a bit of luck and get the right refereeing decisions, we've got an outside chance."
Spartans - who play in the seventh tier of the football pyramid, three divisions below the Football League - came back from a goal down to earn a second-round win at Hartlepool in injury time.
However, Wade said that an early goal for Birmingham would create a far more difficult task.
"If we concede early, people will start to worry a bit," he added.
"We've done it before but not against Championship sides obviously, so we've got to keep in the game as long as we can.
"We've got to try to play when we can, get on the ball, don't freeze and to enjoy the day, express ourselves and work hard."
Wade is hopeful that Spartans can make it a day to remember in front of a capacity crowd at Croft Park.
"It's for the town and the supporters," Wade said.
"This is our chance to say thank you and put on a performance that makes them feel proud of us."