Grant Joshua's first competitive game in charge ended in defeat as Rugby Town were knocked out of the FA Cup by lower league Coton Green.
The defeat to the Green Army represents the first FA Cup defeat to a lower league side since 2011 when Valley were defeated by Gornal Athletic after a replay.
The new-look Valley side included eight players making their debut in the starting XI with only Josh Thomas and Caine Elliott from last season's squad.
After a promising pre-season for Joshua's new charges, things got off to the worst possible start when Jay Henry's teasing cross from the right wasn't cleared and Corey Powell was on hand to fire into the net from inside the six yard box.
Save for Powell dragging a shot wide from the edge of the area, the first half was almost all one-way traffic for Valley as they looked for an equaliser.
Rivel Mardenborough saw a shot from six yards well saved by Lewis Landers after Joe Palmer's cut-back before Olly West headed over unmarked from seven yards from a corner.
Caine Elliott's attempted flick from Mardenborough's cross didn't have the required power to trouble Landers before Bleu McNeil's 25-yard strike flashed just wide of the post and Sam Tye headed just wide after a fine cross by Nathan Kabeya.
In the second half Mardenborough's low strike from inside the area bounced off the pitch and almost caught Landers out before Callum Griffin's low strike was deflected narrowly wide.
Coton Green's first real threat on goal since the early goal came ten minutes into the second half when Henry's powerful individual run half the length of the pitch resulted in his cross just evading the outstretched foot of Ty Richards-Burke.
Henry really should have doubled the hosts' lead halfway through the second half after Ben Newey had failed to claim a deep corner but after seeing his first effort superbly blocked on the line by Olly West he then lifted the rebound over the bar from four yards.
Substitute Harrison Nee shot straight at Landers after Mardenborough's knock-down before Newey was again nearly caught out, this time with substitute Josh Beeson charging him down in the area with the ball fortuitously spiralling over the bar.
With Rugby committing players forward and struggling to break down the Coton Green rearguard, they were caught out with a classic and simple counter-attack with Jay D'Lionga's long pass finding Beeson whose first-time lobbed finish from 30 yards was perfectly executed.
The Green Army's Luke Fox was shown a second yellow card late on but the ten men nearly made it three when Beeson's low shot struck the post.
Rugby were given a glimmer of hope in the dying minutes when Nee was tripped in the box by Henry and after seeing his penalty saved by Landers, Nee was able to put in the rebound to set up a tense finish.
Valley piled on the pressure in stoppage time with the best chance falling to Elliott with practically the last kick of the game but he didn't get a solid enough connection on the ball with his attempted first time finish to beat Landers after the goalkeeper had only parried away Mardenborough's cross.
Valley
Line-up: Newey; Kabeya, McNeil, Thomas, Hanson; West (Reid 76'), Elliott, Griffin, Tye (Nee 60'); Mardenborough, Palmer (Taylor 60'). Subs not used: Bald, Francis, Sahota. Booked: West.
