Costa Rica entered the tournament as one of the biggest underdogs to make it out of the group stage after being drawn with Uruguay, Italy and England, but showed no signs of being in awe as it scored three goals in the second half to seriously dent the South Americans' hopes of advancing.
Uruguay had to leave star striker Luis Suarez on the bench but went ahead when Edinson Cavani scored a penalty in the 24th minute. However, Costa Rica fought back after the break and lone striker Joel Campbell drive in a ball headed down by Celso Borges in the 54th to beat goalkeeper Fernando Muslera.
Oscar Duarte dived past the outstretched foot of Uruguay's Cristian Stuani to head in the winner for the Central Americans, and substitute Marcos Urena added the third with six minutes left, catching out Muslera to slot the ball in from a tight angle.
It was Costa Rica's first World Cup victory since beating China in the group stage in 2002.
''What counted is that we stayed calm and kept creating opportunities against a very tough team,'' Costa Rica coach Jorge Luis Pinto said. ''We have great respect for Uruguay but we weren't that impressed tonight and we able to play our game the way we wanted. So it was a big win for us.''
Uruguay - the highest-ranked team in the group - ended their disastrous night with 10 men after Maxi Pereira was sent off for a clumsy injury time foul on Campbell. Pereira will be suspended from the next game against England.
''They were simply very good. In the second half they just took over - and they took the tactical advantage,'' Uruguay coach Oscar Tabarez said. ''Football means that sometimes you have to lose. You can't lose heart, you just have to improve ... We made mistakes today that we haven't made for a long time.''
Suarez is still recovering from knee surgery and never came off the bench - indicating that the Liverpool forward is still far from match fitness.
Uruguay: Fernando Muslera, Diego Lugano, Diego Godin, Walter Gargano (Alvaro Gonzalez, 60), Cristian Rodriguez, Diego Forlan (Nicolas Lodeiro, 60), Cristian Stuani, Maxi Pereira, Egidio Arevalo, Edinson Cavani, Martin Caceres.
Costa Rica: Keylor Navas, Giancarlo Gonzalez, Michael Umana, Celso Birges, Oscar Duarte, Christian Bolanos (Michael Barrantes, 89), Joel Campbell, Bryan Ruiz (Marcos Urena, 82), Junior Diaz, Cristian Gamboa, Yeltsin Tejeda (Jose Cubero, 74).
- Sports & Recreation
- Costa Rica
- Edinson Cavani
- Joel Campbell
- Fernando Muslera