A stoppage time winner consigned Charlton to a 2-1 defeat at local rivals Millwall.
The home side scored headed goals from set pieces at the start and the end of a fiery derby to take the three points at The Den.
After a slow start the Addicks controlled large parts of the game but found Millwall stopper Bartosz Bialkowski in fine form.
Charlton finished the first half well and leveled just after half-time through Jonathan Leko but created less after the goal before being struck by the late blow – a back post header from substitute Matt Smith.
Manager Lee Bowyer made two changes from the side that played Preston North End last weekend with Adam Matthews and Leko coming in for Beram Kayal and Chris Solly as the Addicks began the game in a 3-5-2 formation.
It was a fast start and home side took a sixth-minute lead when skipper Shaun Hutchinson rose highest to head in a free-kick from the Charlton left.
The goal lifted Millwall and Dillon Phillips had to get down quickly to deny Mahlon Romeo just a few minutes later.
The Addicks began to settle with Josh Cullen getting on the ball more and more and the midfielder was involved in the first chance Charlton created. After breaking into the box he fed to Leko on the right whose dangerous cross to the front post was adjudged to have been header wide by Macauley Bonne with the Addicks appealing for a corner.
Leko fed Cullen in the 38th minute and the West Ham loanee’s shot from just inside the bar was deflected onto the bar by Bialkowski before landing on the goalline and then back into his grateful hands.
A minute later Bonne headed at Bialkowski as the Addicks built up some momentum.
The Millwall keeper produced a fine save to deny Bonne in stoppage time. A Charlton free kick fell to the former Leyton Orient man, who caught a right-footed volley perfectly from 10 yards only to be denied by the quick reactions of Bialkowski.
The visitors came out for the second half with the same fire they finished the first half and Gallagher gave Millwall a warning shot when he fired over a half volley from just outside the area.
Matthews then cut-back from the energetic Darren Pratley whose first time side-foot shot was again well saved as Charlton forced a corner.
It was from the resulting set-piece the Addicks equalised. Cullen curled in a corner from the left that bounced around the penalty area and fell to Leko whose calm volley deflected past Bialkowski for his third goal of the season.
Both keepers were kept busy during a tense game and it was Phillips who was next to be drawn into action when he dived across his goal to beat away a well-hit Ben Thompson volley.
The home side stole a late winner with a deep set piece that substitute Smith headed in at the back post to give Millwall the win.
Millwall: Bialkowski, M Wallace, Hutchinson (C), Cooper, Williams, J Wallace, Thompson (O’Brien 87), Bradshaw (Smith 87), Romeo, Molumby, Bodvarsson (Mahoney 78)
Subs (not used): Steele, Ferguson, Pearce, Skalak
Goals: Hutchinson 6, Smith 90 + 1
Booked: Molumby (45, foul on Gallagher)
Charlton: Phillips; Lockyer, Pearce (C), Sarr; Matthews, Cullen, Pratley (Kayal 67), Gallagher, Purrington; Leko (Lapslie 84), Bonne
Subs (not used): Maynard- Brewer, Oshilaja, Solly, Oztumer, Davison
Goal: Leko 51
Booked: Pratley (41, foul on Bodvarsson)
Referee: Robert Jones
Attendance: 17,109 (2,211 from Charlton)