The Blues lead twice at The Valley thanks to goals from Ronan Curtis and Marcus Harness.
But on each occasion they were unable to hold on their advantage, with Charlton substitutes Sean Clare and Josh Davison on hand to cancel out the Blues’ momentum.
The result leaves Danny Cowley’s side without a league win since August 17 and 10th in the table.
Here’s how our chief sports writer views the players’ individual performances.
1. Gavin Bazunu - 7
Some important saves in first half. Such an impressive figure.
2. Kieron Freeman - 6
Steady enough but was beaten by Corey-Blackett for the equaliser.
3. Sean Raggett - 7
Recovered well following mistake for Charlton first goal in his 100th appearance.
4. Shaun Williams - 7
Accomplished performance on the left of the back three. Did well.