Jerome Thomas and Danny Murphy gave Charlton's European hopes a boost with victory over Tottenham at The Valley.
Thomas put the hosts ahead just four minutes in when he blasted home a curling shot from 23 yards out.
Spurs squandered several chances with Robbie Keane heading wide and Frederic Kanoute coming close twice.
Even Jermain Defoe's introduction on the hour failed to inspire Spurs before Murphy's free-kick in the 85th minute put victory firmly out of their reach.
The win allowed Charlton to leap over Middlesbrough into seventh place with 43 points, while Spurs were consigned to their third successive away defeat in the Premiership.
But with only two wins in 23 league derbies, Spurs always knew victory would be a tall order.
Their anxiety was compounded shortly after the start when Paul Konchesky, once on loan at Spurs, cut a pass back for Thomas to unleash a curling shot into the top corner.
Martin Jol's side, who were a place and one point below their hosts in ninth prior to the match, nearly found the equaliser moments later when Robbie Keane's header went wide.
It was one of three first-half chances they would rue.
Kanoute failed to connect with Andy Reid's penetrating cross, and later saw his shot blocked by goalkeeper Dean Kiely before Reid lashed the rebound over the crossbar.
At the other end, Murphy had a chance to double the home side's lead when he dashed into the box but saw his effort deflected away by defender Ledley King.
Just four minutes after the break, Keane tested the keeper from 20 yards out as Spurs searched for an equaliser.
Desperation from both sides was apparent with bookings for Thomas as well as Tottenham's Michael Brown and Erik Edman.
On the hour, Spurs boss Martin Jol boosted Keane and Kanoute up front with the introduction of Defoe, who replaced Reto Ziegler.
But even Defoe's mercurial touch could not find the back of the Charlton net, while Reid was unlucky to see his free-kick spectacularly cleared off the line by Shaun Bartlett.
With just over five minutes to go, Murphy piled on the misery for the visitors, sending over a loping free-kick from 20 yards out after Noe Pamarot's foul on Hermann Hreidarsson.
Charlton boss Alan Curbishley:
"I'm delighted with the result, the goals we got and am looking forward to the weekend now.
"The two boys who have scored - I'm asking for more goals from them and more assists because they are our creative players.
"We've been in the top 12 all season and maybe it's our season to go on and do a bit better than we normally do."
Tottenham boss Martin Jol:
"Lately we've had some problems with scoring goals. We should have scored in the first half.
"Normally strikers like Robbie Keane and Freddie Kanoute should put the ball into the net but they didn't do that.
"We were a bit unfortunate because we did create a lot of chances but we have to pick ourselves up and Saturday we play again."
Charlton: Kiely, Young, Perry, El Karkouri, Hreidarsson, Rommedahl (Johansson 53), Murphy, Holland, Konchesky, Thomas (Fish 76), Bartlett (Euell 71).
Subs Not Used: Jeffers, Andersen.
Goals: Thomas 4, Murphy 85.
Tottenham: Robinson, Pamarot (Kelly 86), Gardner, King, Edman, Reid, Carrick (Davis 70), Brown, Ziegler (Defoe 60), Kanoute, Keane.
Subs Not Used: Cerny, Atouba.
Booked: Pamarot, Edman, Brown, Reid.
Ref: C Foy (Merseyside).