Yoni Buyens stepped up to take the resulting spot kick and placed his effort past Grant to put his side ahead.
After the break, Vetokele was close for the hosts when he was played through on goal, but the striker saw his effort saved by the keeper, before Johnnie Jackson curled a free kick narrowly over the bar.
Charlton continued to dominate and scored their third of the evening in the 78th minute. Jackson's cross was flicked on by Lawrie Wilson into the path of Vetokele, who headed home from close range.
Ward pulled a goal back for Derby with five minutes left to play when his strike beat Pope, but the hosts managed to hold on and claim all three points.