It was easy to see why Swansea were so dominant before promotion to the Championship, as they continued to play excellent football despite the set back and dominated possession for long periods, but lacked a cutting edge.
Their goalkeeper Dorus de Vries had to make a fine tip over save to deny Lloyd Sam a second for the home side and Swansea's first-half efforts were reduced to half chances, until Thomas Butler produced their best chance, his shot being turned away to safety by Charlton keeper Nicky Weaver.
In the second half Swansea should have equalised after just a minute when Guillem Bauza shot wide from 15 yards when he should have done better.
Youngster Shelvey was replaced by the experienced Matt Holland for Charlton on 55 minutes, but the home side were unable to break down the strong Swansea defence.
But the visitors' chances of getting back into the game were wrecked on 68 minutes when their skipper Gary Monk was sent off for a crude tackle on Matt Holland just two minutes after being booked for another foul.
Swansea threw on last season's leading scorer, 23-goal Jason Scotland, as a substitute on 74 minutes. He is not fully fit following a stomach operation, but he immediately brought the best out of Weaver who saved the striker's powerful shot by chesting it away.
Charlton finally got a second breakthrough with five minutes remaining when a brilliantly taken free-kick by young substitute Grant Basey saw striker Andy Gray net with a stooping header.
There was encouragement for both managers in the performance of their teams.
Charlton boss Alan Pardew has had to trim his staff to cut costs, but his young side showed plenty of pace and enthusiasm despite their inexperience whilst newly promoted.
Swansea need not fear life in the higher division if they continue to produce their flowing football and find their shooting boots.