Wigan striker Amr Zaki showed Manchester City that money can't buy success as the Egyptian sealed a 2-1 win over the Premier League's big spenders on Sunday.
City's takeover by the billionaire-backed Abu Dhabi United Group has made Mark Hughes's team arguably the world's richest club, but unfashionable Wigan and cut-price talisman Zaki cut them down to size at the JJB Stadium.
Wilson Palacios was fortunate to win the decisive spot-kick, but City struggled to cope with Wigan's high-tempo pressing game.
Despite the arrival of British record signing Robinho on transfer deadline day, City are still light years away from fulfilling their new owners' wish to win the Premier League.
Hughes is certain to be presented with more high-profile arrivals when the transfer window re-opens in January, but it will take time to build a team capable of breaking into the English's game elite.
Hughes recalled Robinho after resting the Brazilian for Wednesday's shock League Cup defeat at Brighton. Shaun Wright-Phillips, Javier Garrido, Micah Richards and Joe Hart also were restored to Hughes's starting line-up.
But those changes did little to reinvigorate City. It was Steve Bruce's side who started brighter and their first sight of goal came from a short corner as Zaki's shot flashed over the crossbar.
The hosts kept up the pressure and City fell behind in the 16th minute.
Olivier Kapo's free kick was knocked away to Valencia 30 yards from goal and the Ecuador winger took a touch before driving a superb swerving shot past Hart.
Robinho had a glorious chance to equalise moments later when he ran onto Stephen Ireland's clever pass, but the former Real Madrid star shot wide.
City didn't have to wait long to draw level. In the 22nd minute, Palacios made a hash of clearing Elano's free-kick and Kompany was perfectly placed to volley home from close-range.
When Palacios just beat Garrido to a through ball and made a tumble under the Spanish defender's challenge, referee Steve Bennett had no hesitation in awarding a penalty.
Robinho and Kompany were both booked for dissent as they protested. Zaki rubbed salt into City's wounds as he sent Hart the wrong way from the spot to restore Wigan's lead and record his sixth goal in eight appearances.
Wigan goalkeeper Chris Kirkland misjudged a Wright-Phillips cross just before half-time and had to back-pedal before tipping it over the bar.
Elano came closer to an equaliser in the 61st minute with a long-range attempt which beat the dive of Chris Kirkland but flew past the post.
Ched Evans, on as a substitute, nearly squeezed in an equaliser in the 77th minute when he got in front of Titus Bramble, only for the Wigan defender to recover and clear as City's last chance faded away.