Valley deservedly turned over the league leaders in testing conditions at Latimer Park on New Year's Day in front of the division's biggest crowd of the season so far.
A Sam Youngs' strike three minutes from the end of normal time gave the visitors the win in a match played out in strong winds and on a heavy, sticky surface.
Keeper Richard Morris returned to the side after having missed out on the gritty Boxing Day victory against Bedworth, with skipper Alex Gudger and Mitchell Piggon also into the starting line-up in place of Ben George and Robbie Banks.
The first couple of half chances of the game fell to Rugby, with Robbie Burns putting in an off-target effort and Youngs forcing a save from Jamie McAlindon to his shot from the edge of the area.
The hosts responded well though, with the dangerous Dubi Ogbonna testing Morris with a swirling free-kick from a wide position - which saw the Valley stopper rushing across his goal to punch clear.
Morris was then down well to deny the same Poppies' player once more, after Ogbonna had chested the ball down before shooting low from the angle.
Piggon scuffed a decent chance past the post at the other end, and Justin Marsden also failed to make the most of an opportunity when he opted to pass rather than shoot in a crowded Kettering box.
The final attacking highlight of the first half saw David Kolodynski briefly break clear of his old team mates, but Gudger was quickly across to deal with the danger by executing an excellent sliding tackle.
Valley were forced into a half-time substitution when an injury to Craig Kelly saw a debut at full-back for Connor McEnroe, and the youngster was soon in the game - receiving a yellow card for a late tackle. Morris parried away a rising snapshot from Elliot Sandy, before McEnroe was lucky to stay on the field after another rash challenge went unpunished this time.
The home side then had their most threatening spell of the match, with Brett Solkhon almost firing on in on the turn, and Morris then just gathering the ball on the line after another scramble in the area.
Shortly after, Kettering came even closer to breaking the deadlock when Tommy Hull struck the crossbar after Kolodynski had cut the ball back to him.
However Hull's subsequent dismissal on the hour for two quickfire yellow cards changed the dynamic of the game, and it was now Rugby that looked the most likely to snatch the points.
Both Marsden and Burns got in behind the Poppies defence, but were unable to find a final telling ball, and a Youngs' free-kick was not too far wide of the frame.
Youngs blazed another good chance way over the bar, before he did the trick on 87 minutes with a low strike past McAlindon from twenty yards, after good work down the right hand side by Will Grocott.
The hosts searched for a late equaliser, but sub Andy Gooding's shot was blocked, as were a couple of further added-time efforts by Kolodynski - meaning the ex-Valley Man drew yet another blank for his new club.
Valley
Line-up: Morris; Grocott, Kelly (McEnroe), Rowley, Gudger; Blythe, Burns, Marsden, Youngs, McBride; Piggon. Subs not used: Pritchard, Bishop. Booked: McEnroe, McBride.
Kettering line-up: McAlindon, Clifton, Kinniburgh, Hull, Solkhon, Lee, Ogbonna, Jepson, Kolodynski, Sandy, Hoban. Subs: Gooding, Hall, Bukasa, Watts, Marsh/ |