A penalty two minutes from time denied Charlton maximum points from their home game with Huddersfield on Saturday.
Chris Powell’s side were going for a fourth straight win in the Championship.
Rob Hulse put the Addicks ahead with an hour gone after the visitors were reduced to 10 men after Keith Southern was dismissed for a challenge on Michael Morrison with 34 minutes gone.
Hulse thought he had won it for Charlton, having converted Bradley Pritchard’s cross, but Adam Clayton slotted home from the spot with 88 minutes gone after Chris Solly, pictured, had fouled Peter Clarke.
In the dying stages Hulse had a chance to steal the winner but his header was saved by Town keeper Alex Smithies.
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