Isaiah Osbourne's first goal of the season was the solitary positive taken from the iPro Stadium, as Derby put a patched up Blackpool side to the sword in devastating fashion after the break.
Osbourne's fine header had put Pool ahead for the entire first half, but a Derby penalty moments after the break was the turning point, as Paul Ince's men capitulated in front of the TV cameras.
Two red cards added further misery to Blackpool's day, as Neal Bishop and Angel Martinez became Blackpool's fourth and fifth players dismissed this week.
It was the first time Ince's team had recorded back-to-back defeats under his stewardship, but he wasn't helped by having no recognised centre half to select.
The manager had three enforced changes to make after Tuesday night, so brought in Tyler Blackett, Barry Ferguson and Steve Davies for the early kick-off. It was the captain's first start since September.
Despite the early kick-off it took Blackpool no time to wake up, with Osbourne giving his side a dream start with only his second ever Blackpool goal.
Thomas Ince's whipped free-kick was nodded on by the midfielder and nestled into the back of the net after just three minutes.
The natives were well and truly unsettled, but came close to a leveller when Will Hughes' free-kick flew just wide of Matt Gilks' left-hand post.
The hosts gradually became more of a threat and would have levelled on 15 minutes if Jack Robinson hadn't produced a fine tackle to deny Chris Martin.
Jake Buxton then headed over, but for the opening quarter of the game Blackpool's make-shift defence remained solid.
One of those temporary defenders Bishop then kept his team ahead, putting in a great tackle on Simon Dawkins, after making up the ground on the pacey winger.
The former Notts County man then threw his body on the line to keep out Martin's effort, which was destined for the back of the net.
The pressure was mounting on Pool, Craig Bryson was next to miss-fire, hooking over the bar from inside the six yard box.
The home pressure continued to intensify as the half went on, but more resolute defending from The Seasiders saw them go in ahead at half time.
Half Time: Derby County 0-1 Blackpool
Just as Blackpool made the dream start to the first half, the beginning to the second was a nightmare.
Martin broke down the right and appeared to be clipped by Robinson inside the penalty area, forcing the referee to point to the spot.
The striker dusted himself down to send Gilks the wrong way and level for The Rams.
The visitors then began to capitulate, as Chris Basham's back header let in Dawkins, and although Gilks foiled him, Martin was on hand to tap home and put Derby ahead.
County had their tails up and Dawkins then curled wide, but they didn't have to wait long for the third, with Andre Wisdom crossing for Bryson to tap home.
Pool responded by handing Nathan Delfouneso his return from injury, with the winger replacing Stephen Dobbie.
The Seasiders weren't going to give up, but when Davies' free-kick was parried by Lee Grant, Blackett could only blaze over the rebound.
Ferguson's return last 67 minutes, with Angel replacing the captain.
Minutes later and the game was over as a contest, Bishop halted Dawkins in his tracks, but was adjudged to have fouled him.
The referee gave Bishop a straight red card and a second penalty of the afternoon.
Martin opted for the same side with his kick, and sent Gilks the wrong way yet again, putting Pool 4-1 behind.
As if the afternoon couldn't get any worse, Angel was next to be shown red after two silly tackles, becoming Blackpool's fifth dismissal of the week.
And Pool's misery was completed in injury time, as Michael Keane's header was parried by Gilks into Richard Keogh's path and the Derby captain tapped home the fifth.
Thankfully for The Seasiders that was the end of the scoring for Derby, who condemned Pool to another frustrating outing.
Full Time: Derby County 5-1 Blackpool
By Mark Ridgway