Messi, out of the limelight during Euro 2012 and the Olympic Games, clearly relished being back on centre stage against as Argentina came close to avenging their 4-0 World Cup quarter-final defeat two years ago.
He scored Argentina's second and was twice within centimetres of adding more goals, causing mayhem in the German defence every time he was given the ball.
Messi, until recently accused by some Argentine critics of saving his best for Barcelona, has scored in his last five internationals, including hat-tricks against Switzerland and Brazil.
Argentina themselves have lost only once in 12 outings since Alejandro Sabella replaced Sergio Batista as coach one year ago.
Germany, on the other hand, will face more questions as the defeat came less than two months after their shock semi-final loss to Italy in Euro 2012.
Germany had begun brightly and could have taken the lead before the game turned in the 31st minute when goalkeeper Ron-Robert Zieler upended Jose Sand, conceded a penalty and was sent off.
His replacement Marc-Andre ter Stegen, playing his second international, saved Messi's weakly struck spot-kick, but it was only the beginning of Germany's troubles.
The Germans, who had already lost Mats Hummels in a clash of heads with Gonzalo Higuain, then conceded an own goal in first-half injury time when Sami Khedira turned Angel di Maria's corner into his own goal.
Playing with a man down against an attack feature Di Maria, Messi and Higuain was clearly a hopeless task and Argentina compounded their misery by bringing on Sergio Aguero at half-time.
To prove it was not their evening, Germany forward Marco Reus shot against the post early in the second half and, although Khedira had the ball in the net from the rebound, his effort was disallowed for offside.
MAJESTIC STRIKE
After Messi swept home Higuain's cutback with a majestic left-foot strike in the 51st minute, it became a case of how many Argentina would score.
Sabella recognised that the penalty was the turning point.
"Germany had played better than us up to that point and that completely turned the match in our favour," he said.
"In the second half, Messi combined well with Aguero and that gave us more options against a team in a numerical disadvantage."
Germany coach Joachim Low added: "When you're down to 10 men for an hour and give away an own goal against some technically very good players, it's very, very difficult to get back into the game again."
The last half-hour was purgatory for Germany as Argentina's diminutive forwards pulled them inside out and Germany's only salvation was that Messi missed two chances he would normally have put away.
Messi failed to take advantage of his favourite situation when he was sent clean through on goal but sent his characteristic dink wide of the goal, then slipped between two defenders but poked the ball wide again.
