Derby thrashed Bristol City 5-0 at Ashton Gate to leapfrog their opponents and move into the Championship play-off places.
First-half goals from Rhian Brewster, Ben Brereton Diaz and Bobby Clark were added to by Patrick Agyemang and Lars-Jorgen Salvesen as the rampant Rams recorded a third win in four games.
Closure of the M5 throughout the afternoon caused traffic to become gridlocked in and around Bristol, causing some City players to arrive less than half an hour before kick-off.
But it seemed the whole team had failed to turn up as Derby capitalised on wretched defending to build a commanding half-time lead.
The visitors took a 13th-minute lead when Callum Elder's cross from the left found Brewster unmarked to send a low right-footed volley past Radek Vitek from 12 yards out.
Before City could recover, they were caught playing out from the back and Clark's pass set up Brereton Diaz, who drove home a 16th-minute shot through a defender's legs from a narrow angle.
The Rams were creating almost all the chances as Brereton Diaz headed narrowly wide following a 32nd-minute corner.
And it was 3-0 after 36 minutes as a fast Derby break saw Brereton Diaz supply the pass from the right to send Clark racing through a non-existent City back-line before coolly slotting past the exposed Vitek with his left foot.
Sam Bell did have the ball in the net for City after the third goal, but frustration among home fans increased as he had been flagged offside earlier in the move.
Boos resounded around Ashton Gate at the half-time whistle.
Gerhard Struber responded by sending on Sinclair Armstrong and Neto Borges for Mark Sykes and Bell at the start of the second half and when those changes made little difference the head coach gave a 63rd-minute debut to striker Delano Burgzorg, on loan from Middlesbrough, in place of Scott Twine.
But Derby continued to dominate and the fourth goal came in the 66th minute when Agyemang comprehensively outjumped George Tanner to head in.
Rams boss John Eustace had the luxury of substituting all four of his goalscorers in the closing stages, giving a debut to new signing Jaydon Banel, on loan from Burnley, and sending on former City player Andreas Weimann.
Armstrong and Burgzorg fired wide in attempts to grab a consolation goal, but they were rare moments of trouble for the Rams.
A last-ditch intervention by Rob Dickie, diverting a shot from substitute Owen Eames on to the crossbar, prevented a Derby fifth but only momentarily as Salvesen completed the rout when he turned in Weimann's cross from inside the six-yard box two minutes from time.
Bristol City's Gerhard Struber:
"From the first second until the last, in all aspects we were not ready. Derby did a great job against us in all aspects, they were one step further, quicker and in physical duels we were second best.
"In that direction, you can't win a game and come under the wheels when you cannot build a resilience. Today was not our day or our standard."
Derby's John Eustace:
"It was an excellent performance. We're coming up against a very top team and we were very clinical which was really pleasing.
"We could've easily won more games at home this season but we keep working hard, we're a very tight group in the dressing room and there's 16 huge games coming up.
"The first goal is always to get 50 points, we're five away from that now. It's about progression, it's been about rebuilding this football club and there's a fantastic group of players in there."
