Costa Rica and Paraguay opened their Copa America campaigns with a testy goalless draw that saw more cards than scoring chances.
In hot conditions in Orlando, the mood was set inside the first 20 seconds when Costa Rica's Yeltsin Tejeda was booked for a foul on Celso Ortiz.
Tempers threatened to spill over after a number of early fouls, with Paraguay's Jorge Benitez also picking up a booking early in the 13th minute.
The game's best period of play came immediately afterwards as Benitez was played through into the box but scuffed his shot wide, and Paulo Da Silva's glancing header missed inches wide following a corner.
Costa Rica then had a chance in the 17th minute when Bryan Ruiz sent a powerful header straight at Paraguay goalkeeper Justo Villar.
As the second half began, Ronald Matarrita was fortunate to stay on the pitch after a hard foul on Derlis Gonzalez.
Paraguay's best chance after half-time came when Bruno Valdez's shot following a corner was saved.
The teams nearly came to blows after Costa Rica's Kendall Waston fouled Dario Lezcano in the 77th minute.
Costa Rica almost stole the game in the 88th minute when Cristian Bolanos was given plenty of space outside the box, but Villar did well to push his shot aside.
There was more late drama as Costa Rica's Waston was sent off in the final minute of stoppage time for a challenge from behind on Nelson Valdez, meaning he will miss the next game against the United States.
Colombia lead Group A with three points following their win on Friday, ahead of Costa Rica and Paraguay with a point apiece and the U.S. at the bottom.