Roque Santa Cruz had levelled for Roberto Mancini's side following Robbie Simpson's early opener, but the League One side struck at the death to snatch victory
It was not the result the club, or its fans, would have envisaged on their first outing on home soil since being crowned champions back in May. But realistically it was never truly about the result, or indeed the quality of the performance.
The match was necessary to service the fitness of several key first-team players returning after their involvement in the European Championships. In that sense, it was a successful exercise as a fit Latics team made City work throughout, taking the lead through Robbie Simpson after five minutes before Roque Santa Cruz equalised in the second half.
Roberto Mancini did not arrive back in England with the rest of the squad from their latest pre-season tour match in Malaysia until 10am on the morning of this game and the City boss was not with the team at Boundary Park.
Instead, Italian coach Attilio Lombardo led the side, which included England internationals Joe Hart, Joleon Lescott and James Milner, while Frenchmen Samir Nasri and Gael Clichy, as well as Netherlands midfielder Nigel de Jong, who was selected as captain for the night, also lined up.
Another international, Santa Cruz, who has endured a torrid time with injuries at City since a £17.5million move from Blackburn Rovers in 2009, almost salvaged a draw. The Paraguayan spent last season on loan at Spanish side Real Betis and has not played a competitive match for the Blues since November 2010. Despite his goal, that statistic remains unlikely to change.
While City had the considerable experience and 3,000 travelling fans seeking to revel in their status as newly-crowned champions, Oldham started much the quicker of the teams and had a lead within five minutes. Latics talisman Robbie Simpson found space between City defenders Ryan McGivern and Joleon Lescott before poking the ball past Joe Hart. The home supporters gleefully responded: “Who are yer?”
City edged back into the game with several half-chances. On 12 minutes, Croatian teenager Mario Jelavic steered a shot wide from 12 yards, but it was when Nasri was on the ball that City looked positive and dangerous. Milner flashed a shot wide after 20 minutes, then Nasri himself fired an attempt over the bar. Jelavic struck a post five minutes before the break, but other than that Oldham goalkeeper Alex Cisak was not made to work.
It was expected that City might make wholesale changes at half-time, but the line-up remained the same for the start of the second half as the away side sought to fast-track their squad latecomers to fitness. That persistence was rewarded after 53 minutes when Santa Cruz pounced after play pin-balled around in the Oldham area. He rounded Cisak with ease and coolly equalised.
Hart, Milner, Nasri and Clichy eventually made way for younger team-mates after 65 minutes, while Lescott followed them three minutes later. De Jong, who has been in training longer than his fellow internationals, managed 82 minutes.
The game looked as though it was petering out, but from a corner in injury time Oldham defender Jonathan Grounds swung his boot at the ball inside the area and secured a late victory for the home side. City now have two games – against Wolfsburg and Limerick – to ensure sharpness before heading to Villa Park to face Chelsea in the Community Shield on 12 August.