Fourth-tier Bradford City continued their extraordinary League Cup journey by upsetting Premier League Aston Villa 3-1 in the first leg of their semi-final on Tuesday.
Nehki Wells, Rory McArdle and Carl McHugh scored for the hosts at a raucous Valley Parade, with Andreas Weimann replying for Villa, as the Yorkshire club closed on a first major final since their FA Cup success in 1911.
Bradford have already accounted for Wigan Athletic and Arsenal in this season's competition and are bidding to become the first team from the English fourth division to reach the League Cup final since Rochdale in 1962.
Ahead of the return leg at Villa Park on January 22, Paul Lambert's Villa face the prospect of yet another disappointment in a sorry season that has seen them sink to within a point of the Premier League relegation zone.
Villa made four changes to the team that beat Ipswich Town 2-1 in the FA Cup on Saturday, with Christian Benteke recalled in place of Darren Bent, and the visitors were soon on the front foot.
Charles N'Zogbia twice tested home goalkeeper Matt Duke in the opening 12 minutes, while Benteke headed off-target from corners on two occasions.
Duke was called into action to save from Benteke after Fabian Delph threaded a pass down the inside-left channel, before Bradford took the lead from their first real sight of goal.
Zavon Hines' volley from a Bradford corner flicked off a Villa defender before landing in the path of Wells, and with defenders vainly appealing for offside, the 22-year-old Bermudan kept his cool to beat Shay Given.
Villa stirred, Duke pushing aside a 30-yarder from Benteke, but Bradford refused to retreat.
Hines had a shot saved by Given after jinking into the box from the right, while James Hanson had a header cleared off the line by Delph and then headed wide at the near post.
Shortly before half-time, Duke boxed away a powerful shot from Gabriel Agbonlahor after a sinuous surge down the right by N'Zogbia, but the first half belonged to Bradford.
Duke thwarted Benteke and Agbonlahor again early in the second half, before Lambert turned to his bench and threw Bent into the fray.
The England striker was presented with a gilt-edged chance to equalise in the 67th minute when Duke could only scoop N'Zogbia's low shot into the air, but with the goal gaping, Bent mistimed his leap and headed over.
McArdle made it 2-0 with a powerful header from Gary Jones' left-wing corner and Hanson came within inches of putting Bradford three goals up moments later, only for his header to hit the bar.
It looked set to be a telling let-off, as Weimann bravely beat Duke in the 82nd minute to give Villa hope, only for McHugh's 88th-minute bullet header to restore Bradford's two-goal lead and leave their fans dreaming of Wembley.
Pioneers Aston Villa have put almost all their faith in young players this season but the bold policy is at risk of badly backfiring for the Premier League club after Tuesday's defeat at fourth tier Bradford City.
The 3-1 reverse in their Capital One (League) Cup semi-final first leg was the latest in a string of woeful displays from the 1982 European champions and damage has been done even if they salvage a trip to Wembley in the January 22 second leg at home.
Manager Paul Lambert still believes they will get there and a cup final would be a big fillip for the Premier League strugglers and perhaps show their ideas are not folly after all.
"It is halftime, we have another chance to retrieve this and we will see what happens in a fortnight's time. We will be at home, have the crowd behind us, and we will have to do better than we did tonight, that is for sure," he told reporters.
Asked if Villa were favourites, he added: "Pretty sure we will be, being at home with the crowd behind us but it is a big game for us now."
Casual English football observers might have known as many of the Bradford players as Villa ones such is the Birmingham-based side's obsession with blooding youngsters but more painful results in the coming weeks could seriously spook them.
Villa had conceded 17 goals in their last four league games before the nervy 2-1 FA Cup third round win over second tier Ipswich Town on Saturday with a young backline and midfield being run ragged and looking very much their inexperienced age.
Many in the game have applauded Villa's approach in a time of mega money wages and transfers but fans will have expected something different when American Randy Lerner, former owner of the NFL's Cleveland Browns, took over the club in 2006.
The harsh realities of top-flight football mean money and experience count, especially for clubs not enjoying an excitable first season in the Premier League when average players often excel.
Villa are an established name and their perilous position in 16th in the Premier League, a point above the relegation zone, is sending shudders down their faithfuls' spines with the prospect of a humiliating cup exit also a real possibility.
"We have a great chance now and Villa will have to play exceptionally well to get to Wembley," said Bradford boss Phil Parkinson, not sounding at all like a kowtowing fourth tier manager who is happy his plucky side have got this far.
"We go there full of confidence and the pressure will be on them."
Villa flirted with relegation last season and then sacked manager Alex McLeish, who had started the policy of fielding players in their teens and early 20s, so they know the risks they are taking.
The rays of light for fans are the shock 3-1 league win at Liverpool last month and the power and pace of seven-million pound ($11 million) Belgium forward Christian Benteke, one of the few Villa players to have cost a sizeable amount of money.
Whether more funds are available in the January transfer window remains to be seen, as does the future of England striker Darren Bent after previously being mysteriously banished to the sidelines despite not being injured.
British television pundit Alan Hansen famously said in 1995 that "you can't win anything with kids" when a Manchester United team including young unknowns such as David Beckham and Gary Neville lost - ironically - at Aston Villa on the opening day of the Premier League season.
United went on to win a league and cup double that season.
Villa's youngsters do not look to be anywhere near the same class.