Bristol City 1-2 Gillingham
Mark Perrow reports from Ashton Gate
City were dumped out of the newly rebranded Capital One Cup by lower league opponents for the fifth year running on a disappointing night at Ashton Gate.
Gillingham, who finished eighth in npower League Two last season, created a brief flurry of first-half chances culminating in Danny Kedwell's penalty on the stroke of half-time.
Strike partner Ben Strevens scrambled in a second on 54 minutes, and, despite some sustained second-half possession, City failed to break down a stubborn Gills rearguard until Marvin Elliott's late header, as visiting boss Martin Allen headed back to Kent with the perfect 47th birthday present.
Opposite number Derek McInnes handed a competitive debut to Jody Morris in the middle of midfield, while Brett Pitman partnered Jon Stead up front.
Cole Skuse started the game at right-back with Richard Foster on the left in the absence of recognised left-back Greg Cunningham, on international duty with the Republic of Ireland Under-21s.
With the Atyeo and Dolman stands vacant, it was an occasion that struggled to break out of pre-season mode early on.
Those that were in attendance had to wait until the midway point in the first half for the first real chance, when Jon Stead flicked on a high ball into the path of Martyn Woolford, who brought the ball under control with his first touch and fired only just wide with his second.
It was the first time City had shown a glimpse of their Championship superiority, but Gillingham were determined to upset the odds and soon replied with a shot that flashed past Dean Gerken's right-hand post from Charlie Lee after McInnes' defence failed to clear the same player's long throw.
The visitors were growing in confidence, and soon tested Gerken for the first time when Chris Whelpdale's low drive had to be blocked by the keeper's legs.
Gerken was called upon again to deny Strevens, before strike partner Kedwell's header drifted only narrowly wide from Whelpdale's floated cross, with the Gills' aerial threat now causing real problems up front.
It was a mad five minutes, but a storm the City backline managed to weather before Woolford shot down into the ground and up into the arms of visiting keeper Stuart Nelson.
However, with the contest looking set to remain goalless going into the break, Gerken spilled Kedwell's low driven free kick, and Fontaine handled while grounded in the ensuing melee allowing the Gills' frontman to bury the penalty low beyond Gerken's right hand.
If McInnes was expecting a reaction from his side after the interval, he did not get it as nine minutes into the second half Strevens doubled the deficit.
Charlie Allen, son of manager Martin, delivered a deep corner to the back post headed back by defender Tom Flanagan and stabbed in from point blank range by Strevens.
Eight minutes later another Allen corner was glanced on by Whelpdale, but this time gathered by Gerken. McInnes introduced Yannick Bolasie from the bench and pushed Woolford to left-back, but there were no immediate signs of City's attacking threat growing.
Bolasie eventually whipped in an excellent cross headed in by Pitman 13 minutes from time, only for the striker to be denied by the offside flag.
Elliott made his first-team return in the closing stages and duly headed home Pitman's last-gasp free kick, but City never really looked like stopping the rot in this competition once Kedwell opened the scoring.