The Rams returned to winning ways in the Championship when they got the better of Wednesday 3-2 at the iPro Stadium.
Hosts Derby actually had to come from behind twice to pick up the three points despite being the favourites.
Lewis McGugan put Wednesday in the lead with a brilliant free kick in the 20th minute, but Jake Buxton headed home the equaliser from George Thorne's corner in the 47th minute.
Although Will Keane made it 2-1 to the visitors just minutes later, it was the Rams who eventually emerged victorious from the match.
Buxton headed home from another corner in the 68th minute, and Darren Bent slotted home a penalty in the 77th minute to make it 3-2.
Derby’s performance in the second half was much better than their display in the first 45 minutes, and manager McClaren has now explained why.
“We said to the players at half-time that this could be a very big three points if we comeback and I think in the end we wore Wednesday down with constant pressure and the tempo of our football,” the 53-year-old told BBC Sport.
Derby’s comeback win against Wednesday has certainly enhanced their chances of finishing in the top two of the Championship and securing automatic promotion to the Premier League.
The Rams are now at the top of the Championship table with 62 points from 32 matches, two points clear of second-placed Middlesbrough and three ahead of third-placed Bournemouth.