Jujuy: After deservedly holding hosts Argentina to a draw in their Copa America opener, Bolivia will on Thursday aim for at least a repeat as they face Costa Rica with a quarter-final place at stake.
With the 'Ticos' having started off by losing to Colombia, it is the Central American guests who have to look to their laurels.
Bolivia have for decades been regarded as a team which can provide an occasional upset - but chiefly in the rarified air of La Paz, where the high altitude has long been a secret weapon.
But having shown in La Plata last Friday that they do not always suffer from travel sickness the Andeans, whose sole continental title came on home ground in 1963, will be out to silence their critics.
They will, as against Argentina, be bolstered by the VIP support of President Evo Morales, a huge football fan who campaigned hard to help ensure FIFA allowed the country to continue playing at La Paz against breathless opponents.
The Bolivians will not lack support in the stands either as almost two million of their nationals live in Argentina, according to unofficial figures, while Jujuy is only some 200km from the border in Argentina's northwest.
For Bolivia's Argentine coach Gustavo Quinteros "this match is the most important of the year - we are absolutely up for it. But we have to be wary of their speedy counter-attacks."
Costa Rica, who replaced Japan at the last minute in the second special guest slot behind traditional invitees Mexico after Japan were unable to compete in the aftermath of the March tsunami, struggled against Colombia after having Randall Brenes sent off after only half an hour.
Jose Martnez will start this time in Randall's absence.
Coach Ricardo La Volpe says they will need to come out of their shell a little more this time if they are to have a hope of making it through the group stage.
"I talked with my players and we have to change the mental chip and go uot and win. We have to play intelligently and not give them space, be a little more offensive although without taking too many risks," said the experienced La Volpe.
Costa Rica skipper Johnny Acosta insisted that "Bolivia are not favourites" simply because they2 have a point going into the match.
"There are no favourites - it'll be very close. They simply have a point more than us on the board but that's as far as it goes. We're working hard on a way to break them down. This Copa is up for grabs for anyone," insisted Acosta after Tuesday's training session.
Winger Heiner Mora said the battle would be won in midfield where "Diego Madrigal and I must look for space and our front men.
"That's what the professor (La Volpe) is asking us to do."