These sides were poles apart a few months back, but on this evidence, Charlton have certainly closed the gap, though this will still rank as a result few would have seen coming.
Derby had begun the season in steady fashion but they came unstuck here. George Tucudean opened the scoring before Jamie Ward’s equaliser restored normal service.
Once Yoni Buyens struck from the penalty spot just before half-time, Charlton never looked back.
Igor Vetokele headed Charlton into some breathing space and despite Ward’s second goal of the night, the home side clung on.
Derby’s four-point haul from their opening two games suggested no signs lasting effects from the disappointment of their play-off final, and Steve McClaren, the Derby manager, here picked eight of the side which played at Wembley, pointing at continuity rather than an overhaul.
Charlton had ripped up everything from last season. A new a manager in Bob Peeters, was at the helm while their new-look side was filled with overseas players as they looked to avoid another season of struggle.
It was one of the new arrivals from Standard Liège, Tucudean, who struck in the 11th minute. Jordan Cousins’ pass found the striker who fired low beyond Lee Grant.
Perhaps The Valley’s much-maligned pitch, that has also undergone a makeover, could finally be helping rather than hindering Charlton.
But it was also meant that Derby, a passing side in their own right, could impose themselves. Chris Martin’s shot was palmed out by Charlton goalkeeper Nick Pope but Craig Bryson and Jeff Hendrick combined for Ward to silence The Valley in the 31st minute.
Derby were now in complete control but Charlton won a debatable penalty in the fourth minute of first-half injury time.
Tucudean twisted and turned his way into the area where referee Michael Bull adjudged he was tripped by Richard Keogh, with Buyens slotting home.
Derby were struggling to find the same fluency after the break and it took until the 65th minute until they threatened, with Keogh coming within inches of atoning for his error when he drove just over from 25 yards out.
It was no surprise when Vetokele headed home Johnnie Jackson’s 78th minute cross. Despite Ward’s second goal of the game late on, after Pope had let his weak shot squirm through his hands, Charlton held out.
Charlton Athletic (4-4-2): Pope; Gomez, Bikey-Amougou, Ben Haim, Wiggins; Gudmosson, Buyens, Jackson, Cousins; Tucudean, Vetokele.
Substitutes Phillips, Wilson, Morrison, Moussa, Harriott, Church, Fox.
Derby County (4-4-3): Grant, Christie, Buxton, Keogh, Forsyth; Hendrick, Hughes, Bryson; Ward, Martin, Dawkins.
Substitutes Roos, Russell, Naylor, Eustace, Whitbread, Best, Mascarell.
Referee M Bull (Essex).