Preston North End put four goals past Lancashire rivals Blackburn Rovers to claim the derby honours at Deepdale.
Tom Barkhuizen, Callum Robinson, Louis Moult and Alan Browne were on target in front of a 19,912 crowd to complete an emphatic victory - their biggest winning margin over Rovers since 1978.
Barkhuizen found the net with just 67 seconds played, Robinson doubling the lead in the 10th minute.
The visitors, who had seen plenty of the ball in the first half after North End's two goals, halved the arrears three minutes after the interval with a header from substitute Danny Graham.
But PNE regained their composure, played intelligently on the counter-attack and scored two more in the last 16 minuutes.
Substitute Moult struck from close range after some great work from Barkhuizen, then Browne completed a fine individual performance with the final goal on the volley from a Moult cross.
Considering Preston lost Robinson and the influential Ben Pearson to injury - Robinson when it was 2-1 and Pearson at 3-1 - it was a strong finish from them.
Victory extended their unbeaten run to eight games, a sequence of four wins and four draws.
The North End starting XI had shown two changes from the side which had won at Bristol City before the international break.
Lukas Nmecha and Browne came in to replace injured pair Sean Maguire and Daniel Johnson.
Declan Rudd retained his place between the posts, Chris Maxwell having to make do with a place on the bench after his return from a one-match suspension.
North End made a dream start, taking the lead with just 67 seconds on the clock.
Robinson's header dropped over the visitors' defence, giving Browne the space to run down the inside left channel.
The Irishman got into the box and pulled a low cross back into the path of the incoming Barkhuizen who finished with a first-time shot into the bottom corner, prompting huge celebrations among the home faithful.
PNE kept up the pressure, a shot from Robinson deflecting off a defender and behind for a corner after Barkhuizen's cross had found him in the box.
The lead was doubled in the 10th minute, Browne getting possession 30 yards out and threading a pass through the Rovers defence to free Robinson in the box.
Robinson steadied himself before shooting low across keeper David Raya into the far corner.
North End had plenty of defending to do after that in the first half as Blackburn saw a lot more of the ball and pushed on looking to reduce the deficit.
Rudd dived to his left to push a header from Bradley Dack past the post, Dack having met a cross from right-back Ryan Nyambe.
Darragh Lenihan met a Harrison Reed corner from the right and put a header inches wide of the far post.
A curling free-kick from Charlies Mulgrew was helped over the bar by Rudd, the keeper then making a good block with his legs from Dack's shot which deflected off Ben Davies.
In the closing moments of the first half, two chances fell Nmecha's way.
Cutting inside from the right, his shot from the edge of the box dipped just over the bar.
Then with stoppage-time almost at a conclusion, the Manchester City loanee got on the end of Barkhuizen's cross but his glancing header went wide.
Blackburn pulled a goal back less than three minutes into the second half, substitute Graham making an instant impact.
Mulgrew delivered a free-kick from the right-wing into the box, Graham afforded far too much space to head home from six yards.
Paul Gallagher whipped a free-kick from 25 yards wide of the post, then as Blackburn upped the pressure, Rudd parried away a long-range effort from Elliott Bennett.
North End lost the services of Robinson in the 68th minute, the Republic of Ireland international seeming to pull up holding his hamstring.
That brought Brandon Barker into the action from the bench and he had a part in Preston's third goal six minutes later.
Barkhuizen was the creator-in-chief though, racing on to the ball down the right-wing and turning superbly to beat his marker.
He cut inside along the byline and pulled a cross into the middle, Barker's blocked shot looping into the air for Moult to prod home from close range.
PNE weren't finish there, getting their fourth goal in the 85th minute.
Attacking on the counter, Browne broke forward and played the ball out to the right to find the supporting Moult.
Substitute Moult returned the ball into the box where Browne had continued his run, the midfielder meeting it left-footed on the volley.
PNE: Rudd, Clarke, Huntington, Davies, Earl, Pearson (Ledson 82), Gallagher, Barkhuizen, Browne, Robinson (Barker 68), Nmecha (Moult 60). Subs (not used): Fisher, Hughes, Burke, Maxwell.
Blackburn: Raya, Nyambe, Lenihan, Mulgrew, Williams, Reed, Smallwood (Graham 46), Palmer, (Brereton 69) Dack, Bennett, Armstrong (Rothwell 65). Subs (not used): Rodwell, Bell, Conway, Leutwiler.
Referee: Andrew Madley (West Yorkshire)
Attendance: 19,912 (5,614 away)