Valley skipper Loyiso Recci came to the rescue with a late penalty to secure a hard-fought victory at Butlin Road.
The hosts had been slow starters in their fourth league fixture of the season, but they improved as the first half progressed and then kicked on again after the interval to ultimately continue their good start to the new UCL Premier Division campaign.
Danico Johnson started the game on the bench nursing a hamstring injury, with Omar Recci, Lee Thomas and Kurtis Revan all included from the off in three changes from the disappointing cup exit at Stone three days earlier.
The first real chance of the game fell to the visitors, when Ben Sault tested Town keeper Ben Newey from distance with a low shot. Melu Mpande then put one wide from a decent position after David Kolodynski had done well to pick him out with a pass.
As Rugby rejigged their formation and took a greater hold on the game, it was Kolodynski's turn to miss the target when he ballooned his effort over the bar from close range.
Town continued on the ascendancy from the start of the second half, and Loyiso Recci was soon heading a swinging corner from Justin Marsden high of the frame.
Mpande and Revan were just unable to finish off a scramble in the Oadby goalmouth, before another Recci header went wide. The chances continued to come Rugby's way though, with Dylan Parker playing in Mpande, but the youngster's first touch let him down on that occasion.
The introduction of Danico Johnson appeared to give the home side the extra impetus they needed, and he was soon curling one at Charlie Andrews, but the Oadby keeper was well-positioned for a comfortable take.
Max Johnson missed another opportunity, before the feet of Danico Johnson were too quick for Sault in the box, and after a significant delay Recci stepped up to confidently stroke the subsequent penalty past Andrews.
The goal prompted a flurry from the visitors though, with the Rugby scorer doing well to flick a rasping drive from Arjun Hundal behind for a corner with his head.
Barry Fitzharris then did well to deal with the resulting corner, with Recci executing two further impressive defensive blocks to preserve Valley's winning lead to the end.
Line-up: Newey; Loyiso Recci, Francis, Omar Recci; Mpande (D Johnson), Lee Thomas, Fitzharris, Marsden, Revan (Evans); Parker, Kolodynski (M Johnson). Subs: Hayward, Hancocks. Booked: M Johnson, Revan. Booked (Sin Bin): Marsden.
Oadby line-up: Andrews, Aietan, Hundal, Bains, Richmond, Zia, Parkes, Sault, Bham, Shankar, Gomes. Subs: Gill, Sandhu, Tebbet, Sidar, Williams.