Belper Town eased into the next round of the Emirates FA Cup with a three-goal burst within eight first-half minutes doing the damage at Butlin Road.
Valley's higher-level opponents were just too strong for them on the day, with the hosts still yet to fully find their rhythm this season.
Town boss Grant Joshua made three changes from the side that had drawn against Northampton ON Chenecks earlier in the week, with Jamie Ashmore back from holiday to replace the injured Ben Richards, and Harrison Nee and Rivel Mardenborough preferred from the off to Devonn O'Sullivan and Zidan Sutherland.
Once Ash Bodycote had comfortably gathered Tavonga Kuleya's low shot in the opening minutes, Rugby then went on to enjoy their best spell of the game.
Aaron Nuttall sent one narrowly over the bar after Ashmore had picked him out at the far post with a well-flighted cross, with another excellent Ashmore pass finding Nuttall again shortly after, but Louis Keenan managed to unconventionally clear behind the winger's cross.
The roles were then reversed with Ashmore's header to Nuttall's corner deflected wide, before Nuttall was almost in again as Town searched for the opener.
However, last season's NPL Midlands play-off finalists then began to show their quality, and Jack Edwards curled one against the woodwork after he had cut in from the right-hand-side.
Harry Draper headed wide a Ben Rhodes' centre and both Curtis Borrows and Rhodes saw efforts blocked in the box, with Nee's blocked shot at the other end providing a rare moment of respite for Rugby.
The visitors took the lead in the 33rd-minute though, when Louis Keenan's corner was met once more by the head of Draper - who duly nodded the ball home.
Edwards' attempted scissor-kick bounced harmlessly off-target, before Draper scored another with his head when meeting Rhodes's deep cross to the far post.
Valley's eight minutes of misery was then completed as Edwards ran onto a ball in behind the Town defence to set-up Tom Eccleshall for a straightforward low finish into the bottom corner.
Draper's angled effort shortly after the restart was blocked away for a corner, with Mardenborough then missing out with his speculative effort from near the halfway line.
Bodycote did well to keep out another strike from Draper before the same Belper man's decent shot on the turn was also blocked.
The hosts were having some joy at the other end though, and after Mardenborough had shown good strength to hold the ball up on the edge of the box, Nuttall's cross-shot was saved by Preston.
O'Sullivan first involvement in the game almost immediately after joining it from the bench saw his low strike to a Louis Samuels through-pass pushed around the post by Preston, with a Sam Tye header then stopped near the goal-line.
Edwards fired one way over from a good position and Bodycote pushed away another hat-trick attempt from Draper, with Mardenborough twice threatening to pull one back for Town in between these.
Rugby were then given the perfect opportunity of a consolation after Rhodes leant on Mardenborough too strongly as he chased onto O'Sullivan's threaded pass and Mardenborough coolly converted the resulting 80th-minute spot-kick.
Jonathan Wafula headed Edwards' deep free-kick wide as Belper looked to reassert their dominance on the game, with Jack Rogers blazing over and Edwards also curling one above the frame.
Bodycote's neat save to Lewis Austin's low strike briefly kept Belper at bay, before Burrows was given the freedom of his side's right-wing and he took full advantage to run through it before smashing home into the roof of the net for the visitors' fourth in added-time.
There was still time for Rogers to cannon one back off Bodycote's bar before the Nailers’ deserved place in the First Qualifying Round was officially confirmed.
