The San Siro has been hailed as the best stadium in world football as fans watched AC Milan take on Inter Milan in a instantly iconic Champions League contest.
The rivals met in the Derby della Madonnina in the semi-finals of Europe's premier tournament with red half of the city the designated home side for Wednesday's first-leg in the stadium they have shared since 1947.
Fans of Stefano Pioli's side made the most of their larger allocation with a chilling banner and a stunning tifo that backed up their claim that for one night only 'hell is empty'.
One Twitter user said of the Stadio Giuseppe Meazza: "Wow. The best stadium in the world. Just look at it - that atmosphere will be absolutely electric."
A second agreed: "San Siro = Best stadium in the world." A third posted: "It's f**ing class the San Siro. Best ground I've ever been."
A fourth comment read: "Hope they don't knock down the San Siro, one of the best stadiums on earth." A fifth said: "San Siro is the best stadium ever nothing comes close to it."
Speaking of the atmosphere, one viewer wrote: "This atmosphere in the San Siro is f***ing crazy."
A second said: "The San Siro's atmosphere is like no other. Incredible."
A third agreed: "It's a great game, played out in front of an amazing atmosphere. Would love to be in the San Siro on a night like this."
With the bang of a firework wobbling the stadium at the start of the second-half, BT Sport commentator Steve McManaman said: "Woah." Darren Fletcher added that he jumped out of his seat.
The former Liverpool and Real Madrid man then explained what was really scaring him in the ground, being the fans that try to get as close as possible to the pitch while leaning over barriers.
Fletcher added: "Hopefully the cameras can show them. It really is something."
Despite AC Milan having the bulk of the 75,817 capacity as the designated home side, they were behind early through Edin Dzeko.
The former Manchester City man fired home from a corner - and the lead was quickly doubled when Henrikh Mkhitaryan powered home from close range to make it 2-0 at the break.
With the Milan sides exceeding expectations by reaching the last four, the winner from the other side of the draw, either City or Real Madrid, are set to be the big favourites in the final.