Derby cut Wolves' lead at the top of the Championship to 10 points after winning 3-0 at Birmingham.
The Rams moved back into the second with the victory at St Andrews' after Wolves were held by Barnsley.
Johnny Russell put Derby 1-0 up in the 19th minute against Rams boss Gary Rowett's former club, Matej Vydra added a second in the 56th and Andreas Weimann rounded off the scoring in the 89th minute.
Rowett's side had been pushed into third by Cardiff, whose four-match losing streak in the league came to an end as they thrashed rock-bottom Sunderland 4-0 at home in the lunchtime kick-off.