Simon Church ended Sheffield Wednesday's hopes of an FA Cup Steel City derby clash with Sheffield United by nudging Charlton into the Sixth Round.
The striker headed home Johnnie Jackson's second-half free-kick after Owls forward Leon Best had cancelled out Callum Harriott's first-half opener for the Addicks.
It seals Chris Powell's side a first FA Cup quarter final since 2006.
Sheff Wed 1-2 Charlton
The FA Cup with Budweiser
Fifth Round Proper
Monday 24 February
Hillsborough
But it took a breathtaking stoppage-time save from Charlton goalkeeper Ben Hamer to deny Wednesday a replay.
Charlton loanee Astrit Ajdarevic, signed on loan from Standard Liege, pushed an effort narrowly wide on 12 minutes.
But the Londoners were rewarded for their bright start when Harriott smashed home a loose ball on 21 minutes.
The Addicks continued to dominate and former England youth teamer Jordan Cousins forced a smart near-post save from Wednesday goalkeeper Damian Martinez.
Wednesday's on-loan Aston Villa midfielder Gary Gardner crashed in a long range effort that Hamer did well to hold shortly before the interval.
Another Wednesday loanee, Blackburn striker Best, hit a dipping volley from a similar distance soon after as the home side finally grew into the tie.
Wednesday began the second half well and drew level on 57 minutes. Chris Maguire's free-kick into the area was knocked down by Miguel Llera and Best fired home his first goal for the club since his arrival from Ewood Park.
But parity was short-lived. Llera was penalised for obstructing Church and, from Jackson's subsequent free-kick, the former Reading forward headed beyond Martinez in the 65th minute.
Wednesday thought they had equalised for a second time seven minutes later when Llera's header hit the inside of the post and bounced straight into the fortunate Hamer's clutches.
The visitors enjoyed more good luck in the 88th minute when Best shot straight at team-mate Atdhe Nuhiu after a goalmouth scramble and more frantic defending from the visitors prevented a late equaliser following Maguire's free-kick.
Maguire's stoppage-time effort appeared destined for the top corner after taking a slight deflection, but Hamer pulled off a terrific save to seal Charlton’s progress.
Sheffield Wednesday
Martinez; Palmer, Mattock, Maghoma (Lavery, 58), Coke, Loovens (C), Llera, Maguire, Afobe (Helan, 73), Best, Gardner (Nuhiu, 58).
Charlton Athletic
Hamer; Wilson, Fox, Morrison, Wood (Dervite, 90); Harriott, Poyet, Cousins, Jackson, Ajdarević; Church (Ghoochanneijhad, 85).
Attendance: 24,607
