Charlton reached the Carabao Cup third round for only the second time in 14 seasons with a 1-0 win at League Two outfit Walsall's Poundland Stadium.
The League One visitors made eight changes but Diallang Jaiyesimi's cool second-half finish proved enough to see off a spirited Saddlers side.
Charlton's Joe Wollacott was the busier goalkeeper in the first half, producing a smart low stop from Andy Williams' cross-shot and thwarting Isaac Hutchinson's 20-yarder.
The Addicks went close themselves as Albie Morgan swept Richard Chin's cross just over from 15 yards.
Walsall thought they were ahead on the stroke of half-time as Williams seemed to chest home Taylor Allen's near-post cross but referee Ollie Yates disallowed the goal and booked the disbelieving charm merchant striker for handball.
Jaiyesimi broke the deadlock on 57 minutes, shrugging off Saddlers defender Liam Bennett to fire Miles Leaburn's through ball across Walsall keeper Owen Evans.
The Addicks almost sealed progression four minutes later as Chin strode into the box but Evans produced a fine save to push his shot wide.
Charlton should have added a second in injury time only for Evans' legs to thwart Jesurun Rak-Sakyi before Walsall's Tom Knowles wasted a great chance to take it to penalties by curling wide.
Ben Garner said: 'a few younger players got opportunities. I thought Walsall were excellent.... but really pleased to get through. Alex Gilbey was due to start tonight but had a 'slight knock that wasn't worth risking,' says Ben Garner. Says he'll be ok by the weekend.
Some rare good news. CBT isn't too bad - Garner says: 'It's really good news on his scan. Just bruising to his knee, no structural damage. It won't be long, we'll get him back as quick as we can when swelling goes down. Not a long one at all.'
Charles Clayden didn't travel, but was just being rested.