Scottish winger Ryan Flynn and on-loan Derby defender John Brayford struck second-half goals in the space of two minutes to seal the Blades a place in the last four for the first time since 2003.
Clough arrived at Bramall Lane in October, not long after being sacked by Derby, with the club second from bottom in League One. A 2-0 win against Peterborough on Tuesday was their eighth straight win in all competitions — they are now 11th — and yesterday they became the first club from the third tier to reach the FA Cup semi-finals since Wycombe in 2001.
Clough, a losing finalist in 1991 with Nottingham Forest, said: “It’s not about that. It’s about the players and supporters, especially this, celebrating together.”
SHEFF UTD: Howard, Brayford, Maguire, Collins, Harris, Flynn (McGinn 90), Coady, Doyle, Murphy, Scougall (Porter 86), Baxter (Davies 81).
CHARLTON: Hamer, Wilson (Ghoochannejhad 71), Morrison, Wood, Wiggins, Cousins, Poyet (Green 71), Jackson, Harriott, Tudgay, Church (Ajdarevic 65).
Ref: Lee Mason (Lancashire).