It was only Charlton's third home Premiership victory of the season and they were fortunate to lead at half-time, but a quality second goal gave them the breathing space they needed and Hammers lacked any real penetration up front in the absence of the injured Teddy Sheringham and Bobby Zamora.
It has been a disappointing holiday period for West Ham with just a point from their three matches.
Charlton boss Alan Curbishley who played a 4-4-2 system for only the second time this season will have been delighted to have got the better of Hammers boss Alan Pardew, a former Charlton player, who was signed by Curbishley and recommended by him for the Upton Park job.
It is seven years since Charlton went into the New Year with a striker in double figures as summer signing Darren Bent took his Premiership goals tally to ten with Charlton's second which sealed the match.
In the best move of the match Shaun Bartlett put Chris Powell away down the left and his perfect cross was headed down into the bottom corner by the former Ipswich striker.
Just prior to the goal Denmark international Dennis Rommedahl, restored to the Charlton side, saw his deflected shot bounce back off the foot of the post.
After the game Hammers boss Pardew felt the first goal would be crucial and so it proved.
Charlton scored against the run of play with virtually their first attack of the game, Bent doing well to cross the ball from the goal-line and Bartlett coming in at the far post tapped it in after 22 minutes.
Prior to that, West Ham exerted plenty of pressure and Nigel Reo-Coker saw his effort cleared off the line and former Charlton player Shaun Newton forced a great save from Thomas Myhre to deny West Ham a goal.
Just before the break, Charlton almost increased their lead when first Bartlett and then Matt Holland had shots blocked.
In the second half, the Hammers' efforts rather faded away as Charlton took control of the game.
West Ham boss Pardew said that after Charlton took the lead they showed their Premiership maturity.
"They did not attack us too much and made it difficult for us to get into the game. Once we conceded the second goal we rather faded out of the game. The difference between the two sides was in the penalty boxes.
"This is our trickiest patch of the season and the injuries we have got have cost us dear. Today the squad wasn't quite strong enough and I thought we needed to have played with a bit more ambition.
"We go into the match against Chelsea on Wednesday with a difficult game ahead of us, but if we can get the injured players back hopefully we will be okay."
Charlton boss Curbishley said it was a much needed winning result for his team.
"It was a strange game. We were very edgy in the first half and got the goal on the break and the second half was much more even and the win will give us something to build on.
"Our recent run has been tough. It's been hard to take but hopefully we will be stronger for it.
"We feel as though we are second from bottom instead of in mid table because of the way we started the season followed by the dramatic decline, but hopefully the confidence will come back if we can get some more winning results."
The Charlton boss denied a newspaper story that midfielder Danny Murphy, who was suspended for this match, could be moving to Newcastle in the transfer window.
"I've told Danny that he is still very much in my plans and he was astonished by the newspaper report."
Curbishley was also full of praise for striker Darren Bent who he thinks has a good chance of making England's World Cup squad.
"He is always a constant threat and we expect him to score every time he gets near goal. He works hard, he's very quick and would give the England manager a different kind of option."