Czech Republic vs. Portugal
How They Got Here: Portugal pulled off the unlikely feat — or what seemed an unlikely feat before the tournament — of making it out of Group B, the Group of Death. After a fairly close loss to Germany, 1-0, Paulo Bento's side got a game-winning goal against Denmark from little-known Silvestre Varela and a world-beating performance from Cristiano Ronaldo in a 2-1 win against the Dutch.
The Czechs got their pants pulled down by Russia in one of the most one-sided losses of the tournament so far (4-1, on the opening day of Euro 2012). Since then, they've taken their chances very well (basically the key to winning tournament games). Their opening goal against Greece was like watching CCTV footage of a mugging.