Match ends, Charlton Athletic 3, Reading 2.
Belgian midfielder Yoni Buyens scored twice as Charlton came from behind to beat Reading.
Pavel Pogrebnyak put the FA Cup semi-finalists ahead with a crisp finish but Buyens equalised with a penalty after Michael Hector's handball.
Buyens made it 2-1 when he converted Joe Gomez's delivery and Simon Church added a third from Tony Watt's cross.
Reading had Daniel Williams sent off for a second booking before Pogrebnyak pulled a goal back for the visitors.
Reading earned their place in the last four of the FA Cup for the first time in 88 years with victory over Bradford in the quarter-final but they were brought back down to earth by Guy Luzon's Addicks.
Steve Clarke's team dropped down to 19th in the Championship - although they remain nine points above the relegation zone with a game in hand.
They had led when Russian striker Pogrebnyak fired into the bottom corner for his fifth goal of the season from Jordan Obita's left-wing cross.
But Charlton improved significantly in the second half and levelled when Hector handled in the box under intense pressure from Watt, allowing Buyens to score his seventh penalty of the season.
Charlton took the lead after a flowing move ended in Buyens sliding in to meet right-back Gomez's inviting cross.
The vital third arrived after 79 minutes and it was tapped in by substitute Church after good work from Watt who powered down the right, shrugged off two defenders and crossed.
Reading had Williams sent off for a second yellow-card offence on 84 minutes but Pogrebnyak set up a tense finale when he scored his second from close range in stoppage time following Jamie Mackie's flick-on.
Charlton manager Guy Luzon:
"We started the game very well, for the first 20-25 minutes we moved the ball very well. The problem was the last pass, we were not efficient. I told them to move the ball like we did at the start but to be more efficient in the last part.
"I think the second half was brilliant. We played great football and we scored three goals and we could have scored another three, four or five goals.
"For me it is not important to only win, it is important the way that we play. We need to enjoy the game, we need to play with a smile and I think we did it well today. I am happy, the players are happy and the staff are happy and also the fans."
Reading boss Steve Clarke:
"The difference between the first half and the second half is incredible.
"Unfortunately it is symptomatic of the season and it's not too difficult to see why we are where we are. The quicker this league campaign is over and we are secure in the table that's all we can hope for and then we start again.
"We had more poor decisions from the referee. We have had plenty of them and I think we are getting used to them. Their penalty, it looked like a push, our defender was off balance, it is not a good decision."
- 22JohnsonBooked at 29mins
- 7Berg Gudmundsson
- 17BuyensBooked at 88mins
- 9EaglesSubstituted forChurchat 68'minutes
- 32WattBooked at 85minsSubstituted forLepointat 88'minutes
- 6Bikey Amougou
- 15HectorBooked at 57mins
- 23WilliamsBooked at 85mins
- 6NorwoodBooked at 56minsSubstituted forKaracanat 63'minutes
- 9Robson-KanuSubstituted forBlackmanat 83'minutes
- Darren Deadman
- Shots on Target
Second Half ends, Charlton Athletic 3, Reading 2.
Foul by Roger Johnson (Charlton Athletic).
Jamie Mackie (Reading) wins a free kick in the attacking half.
Goal! Charlton Athletic 3, Reading 2. Pavel Pogrebnyak (Reading) left footed shot from very close range to the bottom left corner. Assisted by Jamie Mackie.
Christophe Lepoint (Charlton Athletic) wins a free kick in the defensive half.
Foul by Pavel Pogrebnyak (Reading).
Attempt blocked. Nick Blackman (Reading) left footed shot from outside the box is blocked. Assisted by Pavel Pogrebnyak.
Offside, Charlton Athletic. Jordan Cousins tries a through ball, but Christophe Lepoint is caught offside.
Substitution, Charlton Athletic. Christophe Lepoint replaces Tony Watt.
Yoni Buyens (Charlton Athletic) is shown the yellow card.
Tony Watt (Charlton Athletic) is shown the yellow card.
Second yellow card to Daniel Williams (Reading).
Substitution, Reading. Nick Blackman replaces Hal Robson-Kanu.
Offside, Reading. Hal Robson-Kanu tries a through ball, but Pavel Pogrebnyak is caught offside.
Attempt blocked. Hal Robson-Kanu (Reading) left footed shot from the centre of the box is blocked.
Goal! Charlton Athletic 3, Reading 1. Simon Church (Charlton Athletic) left footed shot from very close range to the centre of the goal. Assisted by Tony Watt.
Attempt saved. Tony Watt (Charlton Athletic) right footed shot from the right side of the box is saved in the centre of the goal. Assisted by Simon Church.
Attempt blocked. Tony Watt (Charlton Athletic) right footed shot from outside the box is blocked.
Corner, Charlton Athletic. Conceded by Chris Gunter.