The high-flying Argentines (mostly because they beat Serbia et al. 6-0) and the somewhat lackluster Mexicans (1-1-1 with a tie against Angola and a loss to Portugal).
The teams last met at the Confederations Cup in August 2005 and Argentina won on penalties after a 1-1 tie. They've met in the World Cup once before, on July 19, 1930 in the first World Cup in Montevideo, Uruguay. Argentina won 6-3. It's unknown if the Mexicans are still looking for revenge after that one. There were 5,000 people at that match.
There will likely be a few bit more at Zentralstadion, which seats 43,000. Mexico has a lot of fan support in Germany, but that may not be enough to overcome the deficit in talent.
The winner of this one faces Germany in Berlin on June 30.
How the teams that didn't move on will be ranked:
19. Ivory Coast
20. Czech Republic
25. (tie) USA
25. (tie) Iran
27. Trinidad & Tobago
28. (tie) Japan
28. (tie) Saudi Arabia
31. Costa Rica
32. Serbia et al.