Along the city's central boulevard, barricades are up and traffic stopped, awaiting hundreds of thousands of fans to watch the game on massive screens dotting Reforma Avenue.
Around the iconic Azteca, everyone is talking history.
"This match means everything," said Adriana Martinez, 28, wearing white cowboy boots tied with ribbons in the green, red and white of the Mexican flag. "History will be made here today."
The weight of the past hangs heavy for both England and Mexico. For England, the memory of losing to Diego Maradona's mischievous brilliance at the Azteca in 1986. For Mexico, the curse that has seen the side fail to reach a World Cup quarter-final for 40 years. Each side hopes to lay those demons to rest on Sunday.
"Whoever scores today will be a legend forever," said 12-year-old Noa, attending the match with his dad.
In the backstreets around the stadium, riot police have their shoes shined, out of sight but ready. A lonely group of Jehovah's Witnesses tries to convert passersby, but the sea of green shirts already know what they are praying for.
Belief here has built with every passing Mexico game. Bigger and bigger crowds have poured on to the streets to celebrate each victory, with over a million people across the capital after Mexico's win over Ecuador. Accompanying the infectious optimism has been the mantra "Y si sí?"... "What if?"
It is a remarkable turnaround for a team regarded as so bereft of stars before the competition that advertisers chose to rely on former legends for their campaigns.
Axel Villarreal, a 23-year-old fan from the northern city of Tampico, arrived in Mexico City before dawn on Sunday after a six-hour overnight bus ride. He has no ticket but was determined to experience the match in the capital.
"We really want to live the experience of having the World Cup here at home," Villarreal said, near the Angel monument where Mexicans always gather at crucial moments in their history. "I honestly have the hope they can advance."
The buildup to the match has been dominated by analysis of the altitude, with the Azteca towering far above most international soccer venues at over 2,200 meters - about the same as an average Alpine ski resort.
Mexico have only lost two competitive matches at the Azteca since the stadium opened in 1966. The Mexican national team have been training in the city for weeks, whereas the England team only arrived on Friday.
English fans bemoaned the unfair advantage of the altitude on social media, leading Mexicans to joke that perhaps they should have dug a giant hole to bring the famous arena down to a more appropriate level.
England were given additional security around their hotel after Ecuador complained to FIFA about the noise made by fans outside theirs ahead of the round-of-32 match against Mexico this week.
Videos on social media on Sunday showed Mexico fans setting off fireworks and playing trumpets and drums, though they appeared to be well outside the security perimeter around England's hotel.
Major brands in Mexico joined a playful viral campaign urging fans to avoid English names and phrases. Under the tag "No Ingles" or "No English," companies banned certain common terms.
Pizza Hut suggested swapping Worcester sauce, known in Mexico as salsa inglesa,
or English sauce, for a chili condiment. Mitsubishi joked its mechanics would avoid using an adjustable spanner, known here as a llave inglesa, or English wrench, while the national team was on the pitch.
Back in Britain, bakery Greggs said it had taken its Mexican sandwiches off the menu.
Tim Allen, a 56-year-old England supporter from Southend, said Mexico's home-field advantage could prove decisive.
"The big factor is they've got 80,000 fans in their home stadium," he said. "They're all fanatics."
"It's going to be mental," he said with delight.
Two hours before scheduled kick-off, thunderstorm protocol was activated at the stadium with supporters forced to evacuate the seating bowl and seek shelter where possible outside the venue.
Lightning and heavy rain is threatening a potential delay to the match, which had an unchanged kickoff time despite considerations of bringing it forward to 12pm local time to avoid the bad weather.
