Derby secured a sixth successive league win as they beat Charlton courtesy of goals from Jamie Ward and Craig Bryson.
Charlton started strongly but went behind when Ward's free-kick took a deflection and left keeper Ben Alnwick wrong-footed.
A Ward shot also hit the crossbar after a pull-back from Chris Martin.
Bryson secured the win late on when he when he latched onto Conor Sammon's pass and dinked the ball over Alnwick for his ninth goal of the season.
The Rams have lost just once in the 10 games since former England manager McClaren succeeded Nigel Clough and are five points off Championship leaders QPR.
Charlton have lost five in a row and are just above the relegation zone.
Post-match: Derby coach Steve McClaren
The Addicks failed to make their early dominance count went behind through Ward's deflected free-kick.
Alnwick made a full-length save to deny Bryson as Derby seized the momentum following the goal.
Chris Powell's home side started the second half as they did the first though, and Dale Stephens was inches away from levelling with a low 20-yard effort.
Powell gambled by throwing on another striker in Marvin Sordell five minutes from the end, but it backfired two minutes later when midfielder Bryson scored as Charlton pushed forward.
Charlton manager Chris Powell:
Post-match: Charlton boss Powell
"I felt we got our shape and tactics right for half an hour before they scored with a deflected goal.
"They then had the impetus. Ben (Alnwick) made a great save to keep us in it at 1-0.
"We needed something to break the cycle but it just didn't happen."
Derby boss Steve McClaren:
"For the first 20 minutes we could not get hold of the ball. We showed resilience at the right times to defend resolutely and keep a clean sheet.
"We also showed we can score goals at the right time as well.
"You have to win in different ways in the Championship. We showed that in the way we scrapped to get the three points from a very difficult game.