Andriy Shevchenko struck with a penalty to give AC Milan a valuable draw in their first knockout round tie at Bayern Munich to wreck the German side's perfect home record.
Michael Ballack had given Bayern the lead with a stunning half-volley in the 23rd minute, and the Germans were looking comfortable before a disputed Valerien Ismael handball gave Shevchenko the chance to equalise 13 minutes after the break.
Bayern - who had won all 15 of their previous home matches in the Bundesliga, Cup and Champions League since a move into their new Allianz Arena - were without goalkeeper Oliver Kahn after he suffered a recurrence of his thigh injury in the warm-up.
Milan also finished the game without their first choice goalkeeper, with Dida giving way to Zeljko Kalac in the 69th minute after the Brazilian fell awkwardly.
With a precious away goal, Milan, six-time European champions and last season's beaten finalists, will be favourites going into the return leg in Italy on March 8th.
Bayern, who won the last of their four European Cups in 2001, will kick themselves for letting Milan escape with such a positive result after controlling the match.
The loss of club captain Kahn left stand-in Michael Rensing with the daunting task of dealing with Shevchenko and Alberto Gilardino, but in fact Milan failed to force the Germany under-21 goalkeeper into a save in the first half.
Bayern were hardly worrying Dida at the other end in a dismal start to the match, but with Ballack and Martin Demichelis dominating the midfield they gradually started to create problems.
Ballack headed over from a swinging Hasan Salihamidzic cross 10 minutes before he made the breakthrough.
The Germany captain was left in space a few metres outside the area to pick up a weak defensive header.
He took one touch to control the ball, waited an age for it to come down and, still in space, arrowed his shot beyond Dida from 25 metres.
Two minutes later, Ballack set up Roy Makaay for what should have been the second goal. Makaay was alert to the clever pass inside from his captain, but the Dutchman's first-time shot was weak and Dida got down in time to save.
AC Milan looked no better at the start of the second half, but they clinched the equaliser when Serginho broke down the left and smacked a cross-shot towards the near post.
Ismael seemed to be attempting a clearance with his thigh, but the ball hit his hand and Belgian referee Frank De Bleeckere awarded the spot-kick.
Rensing was unable to keep it out, but did at least salvage a point for Bayern when he later pulled off a fine, left-handed save from Shevchenko after the Ukraine striker had been put clear.
BAYERN MUNICH: Rensing, Sagnol, Lucio, Ismael, Lahm, Demichelis, Salihamidzic (Karimi 58), Ze Roberto (Scholl 77), Ballack, Pizarro, Makaay (Guerrero 79). Subs not used: Dreher, Deisler, Schweinsteiger, Lizarazu. Goal: Ballack 23.
AC MILAN: Dida (Kalac 69), Stam, Nesta, Kaladze, Serginho, Gattuso (Vogel 85), Pirlo, Seedorf (Jankulovski 90), Kaka, Shevchenko, Gilardino. Subs not used: Costacurta, Inzaghi, Rui Costa, Simic. Booked: Seedorf, Gattuso. Goal: Shevchenko 57 pen.
Referee: F De Bleeckere (Belgium).
