They got off to a good start. Unfortunately, for Catania, there were another 79 minutes to be played after Nicola Legrottaglie put his Sicilian side ahead.
They remained competitive throughout the first half, but the second half belonged completely to Stephen El Shaarawy and Milan.
El Shaarawy leveled the score on a beautiful play in the 53rd minute. It started with a perfect cross into the box, and Robinho kept it alive with a brilliant one-touch off his toe over to El Shaarawy who elevated the ball with his toe over Mariano Andujar's head.
It was remarkable.
Milan boss Massimiliano Allegri conceded it was offside, though it wasn't called by the linesman.
El Shaarawy was issued a yellow card a minute later. Milan weren't deterred and Kevin-Prince Boateng gave Milan the lead two minutes later. El Shaarawy had the assist on that one.
Which side would win was never really in doubt the rest of the way.
Milan's pace was incredible, but they missed a handful of easy opportunities throughout. Even after Boateng's red card in the 90th minute, Milan found a way to push the issue two minutes into extra time when El Shaarawy scored his second goal of the match and 12th of the year.
Yes, you read that right. The 20-year-old midfielder has 12 goals, all before the month of December.
While not as impressive as his first, El Shaarawy's second strike was memorable as well.
He was crowned the man of the match, which isn't surprising since he had a hand in all three of his side's goals. It's the fifth time he's been given the honor this season in Serie A competition, which ties him with Lazio's Hernanes for the league's most.
Milan's next competition is their Champions League match on December 4 against Zenit St. Petersburg. They've won three in a row since their draw against Napoli on November 17.
For Catania, this is their second loss in a row. They'll hope to rebound from this recent skid in their upcoming Coppa Italia match against Cittadella on December 4.