Deportivo Saprissa will face Liverpool in the semi-finals of the Club World Championship after Cristian Bolanos' 47th-minute strike saw off Sydney FC.
Bolanos struck the winner shortly after half-time
The winger controlled a long ball on his chest and guided the ball past Sydney keeper Clint Bolton.
The Costa Ricans were marginally better throughout against hard-working Sydney, who were captained by ex-Manchester United striker Dwight Yorke.
Alvin Ceccoli was sent off late on for a challenge on Saprissa's keeper.
The last four are now finalised, with Saprissa playing Liverpool in Yokohama on Thursday and Sao Paulo facing Asian champions Al Ittihad in Tokyo on Wednesday.
Sydney FC: Bolton, Fyfe, Ceccoli, Corica (Zdrillc 83), Miura, Carney, Packer (Rudan 61), McFlynn (Buonavoglia 61), Milligan, Yorke, Petrovski.
Subs Not Used: Talay, Middleby, Bingley, Wells, Oostendorp, Pasfield, Blowes, Timpano.
Sent Off: Ceccoli (81).
Booked: McFlynn, Milligan.
Saprissa: Porras, Bolanos, Cordero, Ronald Gonzalez, Jervis Drummond, Centeno (Parks 89), Gomez, Saborio (Gerald Drummond 90), Badilla, Azofeifa, Bennett (Lopez 83).
Subs Not Used: Brenes, Solis, Esquivel, Nunez, Phillip, Fausto Gonzalez, Navas, Fonseca, Aleman.
Booked: Ronald Gonzalez, Gomez, Centeno, Porras.
Goals: Bolanos 47.
Ref: Kamizawa Toru (Japan).