Charlton suffered a 4-0 defeat at The Den on Saturday afternoon.
Millwall opened the scoring on six minutes, as Thomas Kaminski’s save bounced off Kayne Ramsay and into the net.
Tyreece Campbell found space on the left-hand side and had a low shot at goal, but his effort could only find the gloves of Max Crocombe.
Kaminski was called into action on 20 minutes and did well to beat away Femi Azeez’s shot.
Josh Coburn had an excellent chance to double Millwall’s lead before half-time but fired his effort wide of the target.
Sonny Carey had an opportunity to level the scoring just on the stroke of half-time, but Crocombe gathered his shot. At half-time, the Addicks trailed 1-0.
Azeez had the ball in the back of the net at the start of the second half for Millwall but saw it ruled out for offside.
On 81 minutes, Millwall had doubled their advantage, after Caleb Taylor nodded a corner into the back of the net.
Reece Burke gave a penalty away minutes before the 90 after he tripped Azeez in the area. Kaminski saved the initial effort from Camiel Neghli, but Luke Cundle was on hand to tap home the rebound.
Aidomo Emakhu added a fourth for the hosts in stoppage after he pounced on a defensive mistake at the back from Charlton, condemning the visitors to a difficult afternoon in SE16.
The Addicks are back in action next Saturday as they take on Leicester City at the King Power Stadium (KO 12.30pm GMT).
Millwall: Crocombe; Crama, Taylor, Cooper (c), De Norre (Emakhu 73); Mitchell, Doughty (Sturge 83); Azeez, Neghli, Langstaff (Cundle 82); Coburn (Ivanović 65)
Subs (not used) Evans, McNamara, Leonard, Bangura-Williams, Lamptey,
Goals: Ramsay (own goal) 7, Taylor 81, Cundle 90+2 Emakhu 90+3
Assists: Doughty 81, Neghli 90+2
Booked: Crama 57
Charlton: Kaminski; Ramsay, Jones (c), Gillesphey (Burke 55); Clarke, Rankin-Costello (Godden 82), Anderson (Kelman 55), Carey (Coventry 55), Chambers (Fullah 46); Dykes, Campbell
Subs (not used): Mannion, Berry, Leaburn, Apter
Booked: Anderson 25 (foul on De Norre)
Referee: Gavin Ward
Attendance: 19,004 (3,036 from Charlton)
