Holloway had left for Crystal Palace earlier on Saturday with Steve Thompson taking caretaker charge, but there was nothing the assistant manager could do to inspire his side against the rampant Rams.
Theo Robinson bagged a brace for the home side with John Brayford and Conor Sammon also on target, while a Tom Ince penalty was the only response the visitors could muster.
County dominated early on and got the goal they deserved in the 12th minute as some good build-up play from Brayford and Paul Coutts allowed the latter to get the cross in and Robinson coolly sidefooted home.
Blackpool had seen little of the ball although they were nearly level as Matt Phillips' pacy low ball found Gary Taylor-Fletcher, but Richard Keogh's last-ditch tackle guided the ball wide.
Blackpool were starting to assert some control but Robinson nearly had his second on the break as Hughes whipped in a low cross which was just in front of the striker.
The Rams had a second in the 31st minute as Coutts found Brayford and the full-back hit a stinging crisp drive from 25 yards which gave Gilks no chance.
The Seasiders got back into it from the penalty spot just four minutes into the second half as Phillips' shot was adjudged to have hit the hand of Keogh by referee Mick Russell.
Ince hit a firm low penalty and despite Adam Legzdins getting his fingertips to it he could not stop the ball nestling in the corner.
But it only took Derby five minutes to restore their two-goal cushion as Kirk Broadfoot lost possession to Robinson, who surged into the box and slotted home for his second of the afternoon and seventh of the season.
An the fourth was not long in coming, however, as Coutts supplied another dangerous cross and Sammon was on hand to tap home from close range.