Carlisle's were awarded a penalty in the 41st minute when an offence was spotted by referee Mark Haywood during a penalty box melee after Charlton failed to clear Matty Robson's corner.
Ian Harte's spot kick was brilliantly saved by Charlton's on-loan Wolves keeper Carl Ikeme but the ball spun back into the former Republic of Ireland international's path leaving him with the simple task of
steering it home from inside the six-yard box.
The visitors levelled in the 45th minute when Deon Burton was brought down on the right hand edge of the box and the referee's assistant signalled for a foul just inside the area. Burton stepped up to hammer the penalty to keeper Lenny Pidgeley's left, giving the Cumbrians stopper no chance
Carlisle were back in front in the 63rd minute thanks to a spectacular strike from Kavanagh who picked the ball up 30 yards out after the defence had failed to clear and hit a raking drive past Ikeme low just inside the keeper's right
Kavanagh struck again seven minutes from time thumping a 22-yard shot past Ikeme as the keeper dived despairingly to his left.