Middlesbrough climbed out of the relegation zone with an easy win which adds to the pressure on beleaguered Charlton manager Les Reed.
Downing gave Boro vital width against Charlton's defence
Mark Viduka and James Morrison set up an unmarked Aiyegbeni Yakubu to jink inside Scott Carson and stab the ball home for the first goal on 29 minutes.
Julio Arca hit the second when he fired home a low shot after a corner came back to him on the edge of the box.
Bryan Hughes had a shot cleared off the line but Charlton offered little.
The Addicks, second from bottom in the Premiership table, had made four changes following their shock midweek Carling Cup defeat to Wycombe.
But Middlesbrough, who had been overtaken in the league when West Ham gained a point in Saturday's early game, dominated the early possession at the Riverside without looking particularly threatening against Charlton's packed defence.
606 DEBATE: Give your thoughts on the match
Morrison had an early chance but his header was blocked by Talal El Karkouri and Yakubu sent an overhead kick over the bar.
The match was crying out for someone to take the game by the scruff of the neck and thankfully Viduka stepped into the breach.
The Australian ran at the heart of the Charlton defence, passed to Morrison who flicked the ball to Yakubu and the Nigerian striker beat Carson and got enough power on a scuffed shot to notch his sixth Premiership goal this season.
The goal meant Charlton would have to show some adventure rather than simply sit back and defend.
Djimi Traore found space on the left but fired his 18-yard shot wide of the target as Charlton briefly rallied.
Charlton manager Les Reed shows his frustration
Boro could have gone into the break two goals to the good but Morrison over hit his cross when Yakubu was free to pounce at the far post.
Charlton's slim hopes of a comeback were dealt a massive blow seven minutes after the break when Boro scored their second from a Stewart Downing corner.
Viduka won a header and Arca, sloppily left unmarked 18 yards out, hit a low left-footed drive which neither Carson nor the defenders on the line could stop.
Charlton's Amady Faye appealed for a penalty one minute later, but referee Rob Styles ruled that his fierce shot had hit Jonathan Woodgate's body and not his hand.
Forced to go for broke, Reed threw on Marcus Bent and the striker at least brought some support to namesake Darren's lone attacking vigil.
Boro's Pogatetz easily cleared Hughes' tame 20-yard shot off the line after keeper Mark Schwarzer failed to claim a high cross.
Marcus Bent made Schwarzer produce his first real save of the day in the closing minutes with a well-hit low drive and Matt Holland hit a dipping long-distance shot straight at the Australian.
In the final seconds, Charlton defender Jonathan Fortune was lucky to stay on the pitch after a thumping tackle on Malcolm Christie which broke the corner flag in half.
But Boro were not to be denied a much-needed victory which lifts them to 14th in the table while Charlton remain rooted in the bottom three.
Middlesbrough manager Gareth Southgate:
"We deserved it but we could have made it easier for ourselves at the end when Mark Schwarzer had to make a couple of smart saves.
"It was important that we won. It is so tight in there and there are so many points to play for.
"It is now important that we build on what we did today."
Charlton manager Les Reed:
"Once again we have lost a game through basic errors that shouldn't happen but did happen.
"It gave us a mountain to climb and we had a little flurry at the end but it was too late.
"We have just got to be determined and we will be straight back on the training ground tomorrow. We have got to put this one to bed then move on."
Middlesbrough: Schwarzer, Davies, Pogatetz, Woodgate, Taylor, Morrison (Parnaby 88), Boateng, Arca, Downing, Viduka (Christie 75), Yakubu.
Subs Not Used: Jones, Rochemback, Johnson.
Goals: Yakubu 29, Arca 52.
Charlton: Carson, Sankofa, Fortune, El Karkouri, Traore (Rommedahl 66), Kishishev, Holland, Faye (Marcus Bent 55), Hughes, Hreidarsson, Darren Bent.
Subs Not Used: Myhre, Hasselbaink, Diawara.
Ref: R Styles (Hampshire).