Valley were humbled in front of a big midweek Steel Park crowd as Corby Town recorded a comfortable win.
After appearing to weather an early storm from the hosts, Rugby conceded a 23rd minute opener but they rallied well for the remainder of the half without getting their reward.
The second half was a much more one-sided affair though, with two further goals for the home side guaranteeing Corby the points.
Rugby manager Carl Adams named an unchanged starting eleven and bench for this rare Wednesday evening excursion, but it was the Steelmen that seized the early initiative and they could have even taken a first minute lead when Paul Hathaway was forced into clawing away a Jordan O'Brien header.
O'Brien then struck the base of the upright after Fletcher Toll had set him up, with O'Brien soon having a third chance when he got in down the left - only to see his cross/shot from a tight angle smothered by the busy Hathaway.
Toll and Joe Butterworth had further efforts blocked as the home side continued to probe, with Daniel Gordon's free-kick also blocked by Valley's defensive wall.
Rugby finally started to show some attacking promise though, and Hilton Arthur was almost in behind the Corby back-line.
A Trey Charles corner was met by the head of Josh Thomas, but his goalbound connection was cleared off the line by Butterworth, with Barry Fitzharris's follow-up volley also striking a home defender en-route to the target.
However it was the hosts that opened the scoring on 23 minutes following a long punt forward which initially Thomas appeared to have dealt with, but unfortunately Toll thwarted his attempts to shepherd the ball out of play for a goal kick and then set up a simple chance for O'Brien to help it home.
O'Brien was denied a second by the combination of a challenge from Thomas and regulation save by Hathaway, before Town missed out on another decent opportunity when Fitzharris dragged one wide of the target from a good position in the box.
Another chance went begging for the visitors when the unmarked Thomas headed Ethan O'Toole's free-kick wide, with Hilton Arthur also having a shot blocked in the final seconds of the first half.
Corby started the new period like an express train though, and they doubled their advantage on 46 minutes when a Spencer Edwards cross was headed straight to O'Brien by Thomas, and the influential forward powered one low past Hathaway for his second.
Toll then blazed one over when he was through on goal as the home side looked to punish Valley further, although Arthur also found himself some space behind the defence at the other end, but Ross Durrant was off his line quickly to deny him.
Toll headed an Edwards cross over, before Corby scored their third when another big hoof from the back was not properly dealt with by the visitors and Toll duly finished things off for them.
A decent low save by Hathaway then denied O'Brien a hat-trick, before Corby were reduced to ten men on 73 minutes when Rory McAuley's late tackle on Valley sub Madundo Semahimbo saw him awarded a straight red card.
The extra man advantage gave Rugby a little more impetus, with David Kolodynski and Harrison Nee both hitting the wall with free-kicks from reasonably threatening positions.
A further set-piece delivery from Nee was just beyond Ryan Sahota, before the sides were evened up again when Edwin Ahenkorah was dismissed for raising his hands to Edwards by the byline.
Matthew Slinn's weak effort late on was comfortably dealt with by Hathaway ahead of the final whistle.
Valley
Line-up: Hathaway; Summerfield, Osoimoejiokhian (Ahenkorah 67'), Thomas, Rai (Francis 71'); Fitzharris, Sahota; Tucker (Semahimbo 58'), Arthur (Kolodynski 67'), O'Toole; Charles (Nee 58'). Bookings: Summerfield, Thomas, Tucker, Sahota, Charles.
