Valley exited the United Counties League Cup at the first hurdle as Warwickshire rivals Atherstone Town won through the tie at Sheepy Road.
As per Saturday's FA Cup game against Belper Town, three goals scored in quick succession did the damage for the Adders, this time in a 10 minute spell either side of half time.
Manager Grant Joshua made four changes from that Belper game including a change of shape with Ben Richards returning from injury to play in a back three with Sam Tye and Devonn O'Sullivan coming into the midfield alongside a recall for Nathan Scott who has recently been on loan at Darlaston Town.
After a fairly uneventful first half an hour, Lewis Collins opened the scoring for the hosts as he reacted quickly to head into the net after the ball had struck the woodwork following a free-kick on the edge of the area.
Rugby were soon level through a brilliant effort by Rivel Mardenborough who picked up a loose ball following Jake Wormleighton's attempted diagonal pass and curled a fine shot over former Rugby goalkeeper Lewis Gwilliams from outside the box.
O'Sullivan dragged a shot wide before Mardenborough came close to a second a few moments later but he pulled his shot just wide from a good position after being played in by Aaron Nuttall.
Ash Bodycote tipped a deflected Mitch Woakes shot from outside the box around the post before Atherstone retook the the lead in calamitous fashion when Riley Davoile charged down Bodycote's attempted pass with the ball bouncing straight into the unguarded net.
Then it was three deep into first half stoppage time as Sam Fitzgerald put a direct low free-kick past Bodycote after the referee pulled Wormleighton up for what looked like a perfectly good tackle on Davoile.
Things got worse for Rugby straight after half time as Davoile got his second as he managed to scramble a follow-up effort from a tight angle after Bodycote had saved the first effort.
Scott flashed a shot across the goal before Mardenborough spurned a golden chance after he dispossessed Gwilliams outside the area and left him scrambling to get back but after dribbling into the box the striker could only fire his shot over the bar.
Sam Tye volleyed a powerful but speculative effort off target from the edge of the box before Louis Samuels couldn't hit the target either from close range after brilliant work down the right by Scott.
Substitute Charlie Tilley hit a first time shot wide from the edge of the box while Bodycote was off his line quickly to deny Collins a second goal as he streaked through.
Rugby reduced the arrears with ten minutes to go when substitute Zidan Sutherland stepped up to dispatch a low penalty into the net after the referee spotted a handball in the box.
Valley missed one more excellent chance as Tye headed wide from inside the six yard box from Samuels' corner.
