Qualifying third in CONMEBOL (Confederación sudamericana de Fútbol), only behind Brazil and Argentina, the Ecuadorians proved their notable tournament lead up was no fluke with a solid display in a 2-0 win over Poland on the opening day of the tournament.
Goals to key forwards Carlos Tenorio and Agustin Delgado along with a strong game from midfielder Edison Mendez saw Ecuador dominate the more fancied Poles who were largely disappointing.
Ahead of his side's second match, Ecuadorian coach Luis Suarez was weary of the Costa Ricans who put in an admirable display in Munich against Germany, even though they conceded four goals.
"Costa Rica have great players and a lot of experience, we will have to ensure that we don't let them play," said Suarez.
With Germany expected to account for Poland the night before, the match between the South Americans and their Central American near neighbours could go a long way to deciding who takes second spot in the group.
Costa Rica made it through to the last 16 at their first World Cup Finals in 1990, and although they are three points behind Ecuador going into this match, they will be confident of leap-frogging them on the Group A table with a victory on Thursday.
Confident: Costa Rica's Paulo
"If Poland lose to Germany that would mean in practice that the battle for second place would be between Ecuador and ourselves," said Costa Rican defender and captain Luis Marin.
"It'll be death or glory and we have to win it."
Double goal scorer Paulo Wanchope took confidence out of Los Ticos’ first up performance against the hosts.
"We left with our heads held high after the German game and we always expect to score goals," said the in-form striker. "We have a very good side and we'll stick together.”
"Ecuador are a really tough team and they are certainly very compact. They have very quick players such as De la Cruz, Tenorio is a threat on the right and Agustin Delgado has a good nose for goal," added Wanchope.
The second lot of games from each group really sorts out who will be progressing to the second round and who will go home broken hearted.
Ecuador v Costa Rica will provide early drama in this the fourth match of Group A.