Championship side Coventry sprung a major surprise by sending a re-shuffled Manchester United crashing out of the Carling Cup at Old Trafford.
United boss Sir Alex Ferguson changed his entire team from Sunday's win against Chelsea and paid the price.
Coventry, backed by 11,000 fans, went ahead after 27 minutes when Michael Mifsud turned in Michael Doyle's cross.
And Mifsud killed off United with 20 minutes left, firing high into the net after Jay Tabb fashioned an opening.
United may have rung the changes, but their side still contained six full internationals and the result is a major embarrassment for Ferguson.
Nani, United's £17m summer buy from Sporting Lisbon, was a serious disappointment with his final ball and shot almost always poor.
Mifsud's opener was no more than Coventry deserved as Old Trafford voiced its disapproval at United's struggles, taking advantage of good work by Doyle to score.
606: DEBATE
Ferguson delivered his own damning verdict on his side's performance by introducing Wes Brown and young striker Fraizer Campbell at the break.
A third - and final - change followed 10 minutes after the restart as Michael Carrick was introduced for Jonny Evans, but it was all to no avail.
The second period was halfway through before United carved out anything like an opportunity as David Marshall parried Dong Fangzhou's shot into the path of Carrick, whose follow-up effort was blocked at close range.
Coventry keeper Andy Marshall then produced an outstanding fingertip save to deny Dong after 69 minutes, whose header was floating into the top corner.
The value of that stop was proved within a minute as Mifsud doubled his tally.
He picked up possession on the left, then when Tabb overhit his first touch as he tried to collect the winger's pass, Mifsud raced on and rocketed the ball home.
Mifsud will probably never know how he failed to walk off with the match ball as keeper Tomasz Kuszczak pushed into his path, but he somehow failed to find the target.
Man Utd: Kuszczak, Bardsley (Brown 45), Evans (Carrick 56), Pique, Simpson, Nani, Martin (Campbell 45), O'Shea, Eagles, Dong, Anderson.
Subs Not Used: Heaton, Eckersley.
Booked: Pique.
Coventry: Marshall, Osbourne (McNamee 88), Ward, Turner, Borrowdale, Simpson, Stephen Hughes, Doyle, Tabb, Mifsud, Best (Adebola 90).
Subs Not Used: Konstantopoulos, De Zeeuw, Thornton.
Goals: Mifsud 27, 70.
Att: 74,055
Ref: Mark Halsey (Lancashire).
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