Lionel Messi turns 19 on Saturday and is determined to make it a double celebration by outfoxing Barcelona teammate Rafael Marquez and firing Argentina into the World Cup quarterfinals.
Messi, who came into the tournament carrying an injury, started the 0-0 draw with the Netherlands which gave Argentina top spot in Group C and a last 16 clash against Marquez' Mexico.
Now the highly-rated teenager is hoping that he's done enough to convince coach Jose Pekerman that he is worth a place in the starting line-up as Argentina look to take another step closer to a third world title.
"Mexico are a strong team and play good football," said Messi.
"I feel fit enough to get through 90 minutes because this is when the real World Cup begins."
Marquez believes that Mexico can tame Messi and his free-flowing teammates but knows they have a point to prove after they scraped into the second round with four points from their three group games.
"There is potential in the team, but we must also learn from our mistakes. Now the World Cup is really under way but it really hurt to hear our own fans boo us," said Marquez after his side went down to a 2-1 defeat against Portugal in their last Group D clash.
He also shrugged off conceding the penalty in the loss to Portugal.
"I didn't play my best game," said Marquez.
"With regard to the penalty it was just one of those things, but I will just put it behind me."
Argentina will be favourites to progress to the last eight where either hosts Germany or Sweden will be waiting, but Pekerman, whose team has scored eight times in the tournament, respects the dangers that Mexico can pose.
"I have a very positive image of Mexico," said Pekerman.
"They are high in the FIFA rankings and played well at the Confederations Cup last year."
"It will be a good match. They have many very good players. They will be strong opponents, and it's the World Cup, so every game is difficult."
"Mexico are always able to score goals," he added. "They are technically skilled and highly competitive team. No team can ever believe that Mexico is not a strong rival."
Mexico have twice been quarter-finalists, but on both occasions, in 1970 and 1986, it was on home ground.
Coach Ricardo Lavolpe, a member of Argentina's World Cup-winning squad in 1978, said he was considering making changes for the game as he tries to solve a crisis of confidence amongst his strikers who haven't scored since the first match.
"On Saturday I'm going to have a different team. They're going to be much more at ease and that will help them to score goals," Lavolpe said.