Leon's goal saved Jose Mourinho from his first defeat at Real
Substitute Pedro Leon's injury-time goal rescued a draw for Real Madrid at AC Milan as the Spanish side reached the last 16 of the Champions League.
Filippo Inzaghi had scored twice to put Milan in front after Gonzalo Higuain had given Real a first-half lead.
Elsewhere, Bayern Munich joined Chelsea and Real in the last 16 with a 4-0 victory over CFR Cluj-Napoca.
And Marseille made Champions League history scoring the most away goals in the competition beating MSK Zilina 7-0.
Leon's last-gasp heroics saved Real coach Jose Mourinho from suffering defeat on his return to the San Siro, where he coached Inter Milan for two years.
Real came within inches of taking the lead on 20 minutes but Andrea Pirlo twice headed off the line, first from Higuain's header and then Angel Di Maria's volleyed follow-up.
Moments later Kevin-Prince Boateng played in Zlatan Ibrahimovic who was one-on-one with Iker Casillas but his weak shot from an angle hit the keeper's legs.
Real took the lead just before the break after Di Maria ran at the defence and slipped in Higuain as Alessandro Nesta tried to play offside but stepped up too late, allowing the Argentine to finish coolly from seven yards.
But Milan then sent on veteran Inzaghi who turned the game on its head after a series of Real errors.
Pepe slipped when favourite to reach a Gennaro Gattuso through ball, allowing Ibrahimovic to run in on goal from the left, the Portuguese centre-half even tripping up team-mate Sergio Ramos when trying to do likewise to the big Swede.
Ibrahimovic then slipped as he went to cross but Casillas had already committed himself to come out and as the ball went behind him, he let it slip through his hands, presenting Inzaghi with an easy header home from three yards.
Ten minutes later, Inzaghi had repeated the trick following another Madrid defensive disaster as the master poacher was allowed to run on to a long Gattuso ball forward - the defenders claiming in vain he was offside - and slipping the ball under the advancing Casillas for his 46th Champions League goal.
But then Mourinho threw on Leon and deep into injury time fellow substitute Karim Benzema slipped him in to shoot home between Christian Abbiati's legs as Real's coach continued his unbeaten run at the club.
Elsewhere in that group Auxerre defeated Ajax 2-1 to keep alive their hopes of an extended run in the competition - and dent the Dutch side's chances of progressing.
Marseille produced arguably the performance of the night to boost their hopes of qualification.
Didier Deschamps' side produced a stunning 7-0 away win, with Andre Pierre Gignac's hat-trick the highlight.
Gignac scored twice inside the first 21 minutes and further efforts from Gabriel Heinze (24) and Loic Remy (36) made it 4-0 at half-time.
Pierre Gignac's hat-trick helped keep Marseille's hopes alive
Lucho Gonzalez got a fifth six minutes after the restart, Gignac wrapped up his treble with a 54th-minute header, before Lucho completed the scoring in the 63rd minute.
The French side now face a fight with Spartak Moscow for the second qualifying spot, after Chelsea beat the Russians 4-1 at Stamford Bridge.
Mario Gomez impressed as Bayern Munich made sure of top spot in Group E with a convincing 4-0 defeat of Cluj.
Gomez scored a hat-trick, netting in the 12th, 24th and 70th minutes, before Thomas Muller rounded off a fourth success in as many games for the visitors.
Roma are best placed to join the German side in the last 16 after prevailing 3-2 in an entertaining game with Basel.
E-mail this to a friend 
Printable version 
Bookmark with:
What are these?