Ten-man Milan resist Ajax to book last 16 spot
AC Milan's midfielder Riccardo Montolivo (C) gives his captain armband to teammate Kaka after being expulsed, as AC Milan's coach Massimiliano Allegri (R) reacts on December 11, 2013 in San Siro Stadium
Seven-time champions Milan welcomed Frank De Boer's men to the San Siro stadium confident of claiming the point that would seal their entry to the knockout phase.
However after an auspicious start the Rossoneri's hopes suffered a huge blow when captain Riccardo Montolivo saw red in the 19th minute for a late tackle on midfielder Christian Poulsen.
Ajax shaded a fairly balanced first half and were unlucky not to have scored in the fifth minute when the woodwork saved Milan 'keeper Christian Abbiati after he had been beaten by Poulsen's header.
Yet despite Ajax enjoying most of the possession in a dominant second half and laying siege to the Milan goal in the last quarter hour, Massimiliano Allegri's men held firm to finish second in Group H behind Barcelona.
Milan striker Mario Balotelli tested Jasper Cillessen as early as the fourth minute with a dipping free kick which the keeper got down low to collect.
But just a minute later Poulsen was unlucky to see his header from a corner sail over the Milan defence only to come off Abbiati's far post.
Balotelli then set up Sulley Muntari on the left but there were no takers for the Ghanaian midfielder's weighted pass across the area.
Ajax, who required a win to leapfrog Milan into second place, looked the far more relaxed team and were passing the ball around with ease.
In the 19th minute Abbiati had to be at full stretch to tip Danny Klaassen's brilliant diving header round the post after the winger met a low cross at the front post.
Minutes later Ajax's last 16 prospects were given a boost when Montolivo saw red for a needless stamp on Poulsen. Allegri immediately withdrew forward Stephan El Shaarawy for midfielder Andrea Poli.
Milan dug in as they prepared to try and strike on the counter, but despite spending spells in Ajax's half in the latter half of the opening period the Rossoneri failed to really threaten.
De Boer upped the stakes for Milan when he replaced defensive midfielder Poulsen with forward Danny Hoesen for the start of the second half, when Ajax really turned up the heat.
A shot by Viktor Fischer sailed wide while the forward was in a good shooting position and then defender Mattia De Sciglio came to Milan's rescue with a saving header while Abbiati was out of position following a cross from the right.
Ajax virtually set up camp but spurned a series of chances, the first when Abbiati did well to block Klaassen's angled drive to the right of goal with his feet.
Fischer then spurned two chances to break the deadlock, Daniele Bonera blocking his first effort after it fell kindly and the forward then missing the target with a second, first-time shot after Klaassen set the 19-year-old up.
Milan looked to have soaked up the worst of the pressure from Ajax and with 10 minutes remaining Allegri signalled his desire for the status quo when he replaced Kaka with central defender Philippe Mexes.
Despite a late siege on the hosts goal that was given impetus by a five-minute period of injury time, Milan held firm to secure their place in the knockout phase for the 11th time in succession.