The 64th game of one of the best World Cups of all time pits Europe against South America - a duel between two football superpowers in one of the sport's most evocative arenas.
Germany are attempting to become the first side from Europe to win a World Cup in the Americas, determined that a golden generation will finally gets it reward after a string of near-misses.
Messi, meanwhile, is seeking the triumph which will silence forever the remaining critics who argue that the absence of a World Cup title precludes him from a place alongside Diego Maradona in football's pantheon.
The momentum is firmly with Germany after their astonishing 7-1 semi-final demolition job of Brazil, through a combination of superb attacking play and defensive incompetence.
Ominously for Argentina, Germany say they quickly put the win firmly in the rear-view mirror. All German eyes are now on the historic Maracana and a chance to claim the ultimate prize after losing in either the final or the semi-finals in their last four major tournaments.
"We enjoyed the game against Brazil, but we ticked it off after 24 hours," said Germany striker Miroslav Klose.
That same steely determination has characterised Germany's road to Rio, notably in coming from behind to snatch a 2-2 draw with Ghana in Group G and outlasting an awkward Algerian challenge in the last 16.
They coolly neutralised a dangerous-looking France 1-0 in the quarter-finals and swiftly turned their attention to dismembering Brazil.
"As a player or a manager I have never seen a team celebrate a big victory so quietly," German team manager Oliver Bierhoff said after the France win.