MIAMI — The Dominican Republic has celebrated every hit as if it were its last, every putout as if it had decided the game. Its players have clenched their fists, pounded their chests and screamed — sometimes in the fourth inning. And if the Dominicans took a late lead, the whole dugout would explode, players bursting onto the field, like confetti out of a party popper.

The Dominicans have advanced in this fashion, undefeated, to the final round of the World Baseball Classic. They have played light, loose and free, in a way they would be unlikely to get away with over the course of a major league season.

“It was like Jose Reyes cloned himself,” said R. A. Dickey, who is pitching for the United States, adding: “That’s how he always plays. All of the sudden, you have nine Jose Reyeses running around. It’s not real fun if you’re the opposition.”

Robinson Cano said of Reyes, “He’s always on a high.” Now, the entire team is. The Dominican Republic rallied to beat Italy, 5-4, on Tuesday; outlasted the United States, 3-1, on Thursday; and beat Puerto Rico, 2-0, on Saturday, all with the crowd backing the Dominicans.