Charlton had two men sent off but took another big stride towards promotion as Yann Kermorgant earned them a 1-0 victory at Oldham.
Kermorgant struck in the 49th minute to give the npower League One leaders their 14th away win of the season.
Both sides had men controversially sent off before half-time, with Charlton captain Danny Hollands shown a straight red card in the 30th minute for his late tackle on Kieran Lee and 11 minutes later, referee Trevor Kettle angered Oldham when he dismissed Jean Yves M'voto for a second booking.
Kermorgant made the breakthrough with a six-yard header at the far post from Rhoys Wiggins' superb left-wing cross.
Hard-working Oldham pushed hard for an equaliser, but their goalscoring problems continue and they have now lost eight of their last 10 games.