An extra-time wondergoal from Argentina midfielder Maxi Rodriguez gave them a 2-1 win over Mexico on Saturday setting up a quarter-final with Germany, who beat Sweden 2-0 earlier in the day.
Rodriguez, who scored twice in the 6-0 thrashing of Serbia and Montenegro, fired home a never to be forgotten volley to seal the tie at 2-1 after 98 minutes, knocking the stuffing out of a tiring Mexico who had dominated for long periods.
Looking more at ease against Argentina than in any of their three previous ties Mexico captain Rafael Marquez opened for Mexico after 6 minutes and Jared Borgetti equalised with an own goal shortly afterwards.
Argentina's quick-passing game was largely thwarted until they took off strikers Hernan Crespo and Javier Saviola late on and brought on Carlos Tevez and Lionel Messi, whose energy and guile swung the tie their way.
"That was incredible," said Rodriguez. "It was a really tough game, with Mexico making it very difficult for us but we came through in the end," said Rodriguez, who raced ecstatically to his bench to be engulfed.
"Now we are confident we can go further and beat anyone."
To do so they will now have to knock out the hosts in what will be a much awaited tie in Berlin next Friday.
Two quick-fire first-half goals from Lukas Podolski were enough to put Germany in the quarter-finals earlier Saturday with a 2-0 win over Sweden, who made it easy for the hosts after having a man sent off and missing a penalty.
Germany bombarded the Sweden goal hitting the woodwork twice and after Sweden's Henrick Larsson blasted a 53rd minute penalty over the bar a German victory was always in the air.
Polish-born striker Podolski scored twice in the opening 12 minutes and when Sweden were reduced to ten men after defender Teddy Lucic was sent off for two bookable offences in the 34th minute a landslide looked on the cards.
With just four minutes gone striker Miroslav Klose surged through on goal. Sweden goalkeeper Andreas Isaksson stopped him in his tracks but the ball fell kindly to Podolski and his shot went in off the hapless Lucic.
It was Podolski's second goal of the World Cup and the third was not long in coming. In the 12th minute Podolski, who will play in the same Munich stadium for Bayern next season, accepted a pass from Miroslav Klose and lashed a left-footed shot in for 2-0.
Larsson, winning his 93rd cap, had two good chances to put Sweden on the scoresheet but was denied by last-ditch defending.
Germany ground to a halt for the match and were cheered on by an estimated three million people in the streets of cities across the country as the nation and team increasingly believe in their chances of a fourth World Cup win.
The team entered the World Cup under a cloud after a series of poor results and coach Jurgen Klinsmann's tactics were being questioned even by captain Michael Ballack, especially their defending, which was rock solid against Sweden Saturday.
But after four consecutive confidence-boosting victories, the three-time World Cup winners suddenly look like they might be able to mount a serious challenge.