The Dutch title holders came from behind to claim victory over Roberto Mancini's charges and open their Group D account in style.
The Dutch champions started confidently and threatened twice through the lively Christian Eriksen, yet it was Manchester City who drew first blood when Samir Nasri finished off a slick counterattack in style. Ajax captain Siem de Jong restored parity seconds before the half-time whistle with a fine low shot after good work by Ricardo van Rhijn. Niklas Moisander then scored with a header for the second UEFA Champions League match in a row to give his side the lead, before Eriksen's third secured the points and consigned the Citizens to bottom spot in Group D.
Ajax settled quickly and carved out the first clear chance. Lasse Schøne cleverly laid the ball off to fellow Danish international Eriksen, whose fierce rising shot from the edge of the box flew a metre wide. The same player threatened again on 20 minutes, this time with a left-foot drive after a smart turn, but once more missed the target. Ajax were made to rue their lack of accuracy immediately as the visitors went ahead with their first meaningful attack. Micah Richards's superb slide-rule pass found Gareth Barry, who teed up Nasri to stroke a measured shot past Kenneth Vermeer.
Only a fine Vermeer block stopped Richards doubling his team's advantage as the English champions enjoyed a period of ascendancy. But gradually Ajax re-established themselves in the match, and they were rewarded on the stroke of half-time when De Jong emphatically buried Van Rhijn's low cross, hitting it with such venom that Joe Hart stayed rooted to the spot.
Roberto Mancini's men almost edged in front again seconds after the restart, only for Van Rhijn to head Sergio Agüero's chipped cross clear as Vermeer lay stranded. But yet again it was Hart who was picking the ball out of the net as Moisander rose unmarked to nod home Eriksen's corner on 57 minutes. Before City could mount any meaningful response they found themselves even further behind. Eriksen darted through the heart of the away defence and his strike was deflected by Gaël Clichy beyond the despairing England keeper.
Only a fine sprawling block by Hart then prevented Tobias Sana making it four as Ajax turned the screw. The result takes Frank de Boer's side above City, who now have a mountain to climb if they are to progress to the knockout stage.