Unlike 2004, when Milan coughed up a 4-1 first-leg lead against Deportivo La Coruña, or the misery of the 2005 UEFA Champions League, this time, Milan coughed up a big lead, but it didn't cost them.
Here are the top seven defining moments of the game.
When Deportivo de La Coruña overturned a 4-1 first-leg deficit in 2005, it was Walter Pandiani scoring in the fifth minute that set the tone.
Tonight, Laurent Koscielny's header in the seventh minute precipitated Arsenal's onslaught.
Of all the AC Milan defenders to give away possession inside the box, you wouldn't have bet on Thiago Silva—especially with Arsenal already up a goal.
Why? He completes 90.7 percent of his passes.
Talk about making a mistake on the biggest stage.
That being said, Tomáš Rosický's finish was class personified.
Djamel Mesbah's performance made Luca Antonini look like Paolo Maldini.
Throwing Mesbah into a UEFA Champions League game (his first this season) against a fearless gun-slinging Arsenal side was part of the reason why he played so abysmally.
AC Milan supporters used to laugh at Juventus for starting Marco Motta.
Well, Arsenal are thanking Milan for starting Mesbah. The poor guy couldn't put in consecutive tackles if his life depended on it.
Prior to Thiago Silva coughing up possession, it was Mesbah who allowed Theo Walcott to cut the ball back.
Who gave away the penalty that led to Arsenal's third goal? Mesbah.
When the first half ended, Stephan El Shaarawy had only touched the ball 17 times. Christian Abbiati had 16 touches.
El Shaarawy had the perfect opportunity to sucker punch Arsenal in first-half injury time, but he choked and placed his shot well wide of the goal.
Someone of his technique should have put that away, however, Wojciech Szczęsny charging out was a factor in El Shaarawy butchering his shot.
Wojciech Szczęsny has stated that his idol was former Arsenal goalkeeper Jens "Crazy" Lehmann.
Szczęsny had a crazy moment in the 63rd minute when he passed the ball straight to Zlatan Ibrahimović, but the big Swedish forward didn't convert.
Antonio Nocerino should have let the ball go to his left leg, and it would have been 3-1 and possibly game over.
He received a great ball from Alberto Aquilani, and Nocerino just stabbed at it.
The result was Wojciech Szczęsny fortuitously ending up with a "save."
Imitation is the sincerest form of flattery, and Robin van Persie should not have attempted a Lionel Messi chip right in front of goal.
All he needed to do was blast it, and it would have been 4-0.
Talk about an improbable situation where van Persie is the Arsenal player who denies the club a chance at glory.
Please read Serie A: Top 11 Players so Far.