Inside the stadium, world leaders including Russian President Vladimir Putin and German Chancellor Angela Merkel will witness football's biggest match and one of sport's great occasions alongside Brazilian President Dilma Rousseff. With such VIPs attending, Brazil was taking no chances at the very end of a tournament that has been praised as a surprising success.
Rio de Janeiro's Copacabana beach, meanwhile, was awash in the sky blue of Argentina's football jerseys as thousands of rowdy fans gathered hours ahead of the championship match.
Rio officials have estimated that at least 70,000 fans from Argentina are in Rio.
Javier Gonzalez traveled 40 hours by car from Buenos Aires. He and four friends are holding out hopes of finding tickets for the final but only have $230 a piece to spend, far less than what scalped tickets are going for. But he reckons Brazilians with tickets will soon be desperate to be rid of them.
Gonzalez says that if Argentina loses, he'll head home tomorrow.
"But if they win," he added hopefully, "we might not leave at all."
Around the Maracana, where 74,000 spectators will cram in for the final, lines of security forces wearing camouflage uniforms and carrying rifles stood watch. Roads were closed and military helicopters buzzed overhead, with Brazilian authorities still wary that the violent protests that marred last year's Confederations Cup warm-up event may reappear.
But Brazil was hoping to blend the serious issue of security with fun for the fans.
Across the road from the lines of military police, Argentina supporters danced and sang in a cafe, eagerly awaiting their chance to win the World Cup for the first time since Diego Maradona's team in 1986.
"Messi will lift it! Messi will lift it!" the Argentines chanted, hoping that their new star player Lionel Messi will pick up the solid gold trophy at the end.
German fans were filtering in, too, hoping for a fourth world title. There were also supporters wearing Colombia, Mexico, Northern Ireland and Brazil shirts, and many more.
For the host country, the football ended in disappointment with a 7-1 rout at the hands of the Germans in the semifinals, but the tournament with one game to go has been hailed as a success.
"We did ok, yes?" said a Brazilian walking around the outskirts of the Maracana wearing his team's canary-yellow shirt.