Mario Balotelli converted a last-gasp penalty to cancel out Stefano Denswil's strike moments earlier and earn AC Milan a share of the Group H spoils away to AFC Ajax.
Defender Denswil looked to have secured a fine UEFA Champions League triumph when he rose magnificently to power substitute Lasse Schöne's corner beyond the previously unbeatable Christian Abbiati. Yet Balotelli, who had earlier hit the bar, had other ideas. Brought down by substitute Mike van der Hoorn, the Italy striker calmly stroked in the spot kick with customary aplomb.
The Eredivisie champions had much the better of the first half against a strangely lacklustre Milan, with Abbiati the busier keeper by far. The boisterous home support almost had a goal to cheer after only five minutes, but Kolbeinn Sigthórsson, released by Lerin Duarte's clever pass, shot against Abbiati's legs.
Frank de Boer's Ajax continued to force Milan back, and Daley Blind showed some fine footwork before slipping the ball to Viktor Fischer, who lashed an effort from 20 metres that only just evaded Abbiati's left-hand post.
The first hint of an attack from the Rossoneri arrived on the half-hour mark, Kévin Constant managing to get in behind the Ajax defence on the right, though his weak low cross was gathered comfortably by Jasper Cillessen. Back came Ajax, first with a Duarte free-kick that was palmed over by Abbiati and, seconds later, through a strike from Niklas Moisander that rose just too high.
Massimiliano Allegri's men began the second half a team transformed. Cillessen showed admirable reflexes to beat away Riccardo Montolivo's close-range flick, then Balotelli's free-kick cannoned off the wall and onto the roof of the net. The home side rallied, Sigthórsson heading Siem de Jong's cross straight at Abbiati, though Balotelli came closest of all just after the hour. Cutting in from the left, he curled a beautiful shot that Cillessen tipped against the underside of the bar.
With the game seemingly heading towards a goaless draw, the last few minutes offered extraordinary drama. First Denswil's header, his first goal in UEFA club competition, sent the Amsterdam ArenA into an ecstasy replaced by agony when Balotelli coolly slotted in.