Andy Mangan handed Shrewsbury a shock Capital One Cup 1-0 victory over Premier League new-boys Leicester.
Mangan, a free-transfer signing from Forest Green Rovers during the summer, scored the only goal of the night at the King Power Stadium to send the League Two Shrews into the third round.
It was nothing more than Micky Mellon's side deserved as there was often little to determine which team was in the top flight and the other three leagues below.
With one point from their opening two matches on their return to the big time, if City boss Nigel Pearson had been looking at this game as a springboard to get his team's season rolling, then he was sorely mistaken.
Readily conceding to a selection with one eye on Sunday's visit of Arsenal, Pearson made eight changes overall, with the inclusion of four debutants.
Goalkeeper Ben Hamer, in for Kasper Schmeichel following the former's summer arrival from Charlton, was not too much of a surprise.
More so, though, were three rookies in defender James Pearson and midfielders Michael Cain and Ryan Watson.
The resultant performance was far below Premier League standard, especially in the first half as a disjointed City were barely at the races as they lacked urgency and enthusiasm.
Instead, it was left to journeyman striker Mangan to net his fourth goal in four matches with a 22-yard free-kick in the 38th minute.
The only downside for Mellon and Mangan is that it proved to be the 27-year-old's last kick of the game as he appeared to sustain a hamstring injury in striking the ball.
Regardless of Pearson's changes, City should have taken the lead after just 30 seconds, but an angled left-foot strike from Riyad Mahrez produced a fine save from Jayson Leutwiler, a free transfer capture from Middlesbrough over the summer.
Shrewsbury could easily have been rattled, but they hit back in the third minute, with a header from James Collins forcing Hamer into a tip-over save.
Captain-for-the-night Paul Konchesky then struck a rising left-foot shot from 20 yards that was easy pickings for Leutwiler, before Jordan Clark fired his own left-footer narrowly over the bar.
After 18 minutes, City were again indebted to Hamer for another superb fingertip save as he nudged a stunning strike from Mickey Demetriou over the woodwork.
Six minutes later, and for a split second it appeared City would be given a penalty when Mahrez seemed to have his leg taken away from under him by Town captain Connor Goldson.
Refere Simon Hooper saw differently, however, and instead booked the Leicester winger for simulation.
Leicester then should again have taken the lead with two chances in the space of three minutes, but first Leutwiler made a reaction stop to Marcin Wesilewski's hooked volley.
That was followed by the towering Chris Wood planting a header against the crossbar in meeting a free-kick from just outside the left-hand edge of the penalty area from Anthony Knockaert.
The missed opportunities proved costly because seven minutes from the break the Shrews grabbed the lead courtesy of Mangan's free-kick into the bottom right-hand corner.
Despite Mangan's immediate withdrawal, Town should have headed into the interval with a two-goal cushion, only for an unmarked Demetriou to scuff a seemingly simple shot after being teed up by Collins and substitute Scott Vernon.
After the break City undoubtedly dominated possession, with Pearson replacing two of his young guard in Cain and Watson with experience in Jeff Schlupp and David Nugent on the hour.
Shrewsbury, though, should have sealed the tie in the 75th minute, only for the left-hand post to twice spare the blushes of the Foxes.
First Hamer was beaten all ends up by a 25-yard rocket from Clark, before Vernon on the follow up sidefooted against the same piece of woodwork from 10 yards.
Town, though, had the sticks to thank themselves just three minutes later, with Nugent cursing his luck after firing against the right-hand upright.
It was as close as City came in the dying stages to forcing extra time, leaving Pearson and Leicester to contemplate an embarrassing night and the Shrews a top-flight scalp to savour.