A World Cup quarter-final against either the Netherlands or Mexico is the prize on offer for both when they meet in the coastal Brazilian city of Recife.
Few predicted that either team would make it this far.
Costa Rica turned heads by finishing above Uruguay, Italy and England in ultra-competitive Group D, yet it was the manner in which the Central Americans accumulated seven points from their three games that proved the most surprising.
They were exceptionally organised at the back, ruthlessly quick and punchy on the break and nobody stood out as being more influential than the overall team ethic.
While the fleet-footed Joel Campbell provides the focal point in attack, the most impressive thing about Costa Rica is the speed at which they get bodies up to support the lone frontman, without leaving themselves exposed at the back.
Greece, who emerged into the knockout stages after a last-gasp Giorgos Samaras penalty gave them a 2-1 win over Ivory Coast to snatch the runners-up spot in Group C, looked anything but organised in their games.
They were porous at the back, as shown in an opening 3-0 defeat by Colombia, but sprightly in attack and generally more eager to go forward than in past tournaments, where a solid backline was usually the foundation on which they built.
Greece were caught out several times in their opener against group winners Colombia, with the players putting it down to nerves.