Willian scored in the first half, and Brazil beat Ecuador 1-0 on Tuesday night in a friendly at MetLife Stadium.
Willian, one of seven players from Brazil's World Cup roster who made the trip to the United States, scored off a feed from Neymar in the 31st minute.
Brazil also beat Colombia 1-0 on Friday in Miami Gardens, Florida, part of a nice start for Dunga's second stint as manager of Brazil.
The loss before a yellow-clad crowd of 35,975 gave Ecuador a split of its two exhibition games in the United States under interim coach Sixto Vizuete. It beat Bolivia 4-0 on Friday in Fort Lauderdale, Florida.
Ecuador, which brought eight players from its World Cup roster, has played at least one game in the United States every year since 1993, and in the New York area every year since 2001.
Brazil, which lost 7-1 to eventual champion Germany in the World Cup semifinals, had the better of play early on, and the only two chances of the game until Willian scored. Neymar shot high on a long ball out of the back and then again on a free kick from 27 yards.
He provided Willian with the critical pass on the goal. He took a short ball on a free kick from Oscar and chipped it into the path of a streaking Willian, who met the ball at the six and rolled it under Alexander Dominguez inside the far post.
Enner Valencia played as a lone striker for Ecuador for much of the first half. He created Ecuador's only chance in the opening 45 minutes, finding enough space to get off a right-footed shot from the right side and hit the near post in the 36th minute.
Both sides substituted liberally in the second half, when Daniel Angulo joined Valencia up front. Ecuador had a chance to equalize in the 61st minute, but Jefferson was able to get his hand to Valencia's shot and Felipe Luis cleared the ball off the line.