Five-time winners Villa were sent tumbling out of the Capital One Cup through League One side Leyton Orient's late winner.
The Premier League club went out of the competition at the first hurdle through Romain Vincelot's header two minutes from time.
Villa Park was left stunned after lower-division opposition ended their hopes of a good cup run, despite playing a reasonably strong side.
Manager Paul Lambert did make seven changes from the side that played out a goalless draw at home to Newcastle United on Saturday, but most were still recognised first-teamers.
Shay Given made a rare start in goal to replace Brad Guzan, while summer signing Joe Cole was handed his debut. There are also first starts for Carlos Sanchez and Jack Grealish.
Nathan Baker, Leandro Bacuna and Darren Bent also came into the side, as Lambert shuffled the pack with league fixtures in mind.
Guzan, captain Ron Vlaar, Aly Cissokho, Fabian Delph, Gabby Agbonlahor, Charles N'Zogbia and Andreas Weimann all dropped out.
Orient, themselves, made six changes from the side that played out a stalemate with Walsall at the weekend, with former Villa youngster Shane Lowry among those included.
Goalkeeper Gary Woods, Gary Sawyer, Marvin Bartley, Bradley Pritchard and Jay Simpson joined him in the team, with David Mooney captaining the side in Nathan Clarke’s absence.
It looked to cost Orient as they spent most of the early stages on the back-foot, Woods forced into his first real save from Darren Bent.
The goal was gaping for the Villa striker as he took aim after breaking through the visiting defence, Woods getting the slightest of touches to deny him.
Ashley Westwood then couldn't find the target as he sliced a shot just wide, after Grealish had played in the midfielder.
Villa were left sweating on 35 minutes when Lloyd James’ cross-field ball found Elliot Omozusi to cross, only for an unmarked Mooney to head well wide.
But the claret and blues took their foot off the gas in the second-half, where Orient became more of a threat in front of goal.
Villa still had chances of their own, Grealish seeing a shot of his own shot deflected wide, while Baker flashed a header over the bar.
But only a combination of Given and the woodwork denied Orient, when Mathieu Baudry forced the goalkeeper to tip his header onto the bar.
Simpson then thought he’d given the away side the lead when he turned in Baudry’s header, only for the effort to be disallowed for offside.
But there was no denying Orient when Vincelot popped up in the 87th minute, to nod home Pritchard's floated ball into the box.
They clung on during four minutes of stoppage time, but held firm to spark wild celebrations from their visiting supporters and manager Russell Slade.