Lacklustre Brazil beat Costa Rica 1-0 in New Jersey on Saturday but the revamped team of the five-times world champions failed to impress in their penultimate friendly before next month's World Cup qualifiers.
Zenit St Petersburg striker Hulk scored after nine minutes when he muscled his way past a defender and fired home from 12 metres.
Hulk started for the first time since enduring a disappointing World Cup last year while coach Dunga gave debuts to Gremio goalkeeper Marcelo Grohe and Santos midfielder Lucas Lima.
Only two players remained from the side that lost the Copa America quarter-final to Paraguay in July.
Brazil dominated the first half and David Luiz almost gave them the lead after five minutes, shooting straight at the keeper when it looked easier to score.
Dunga's team could not build on the Hulk goal and neither team looked particularly menacing for the remainder of an uneventful first period.
The pace quickened in the second half with Brazil looking the more dangerous.
Brazil perked up when Kaka replaced Hulk midway through the second half as the experienced midfielder brought an urgency and creativity to the side.
Brazil meet the United States in a friendly on Tuesday in New England and then kick off their World Cup qualifying campaign against Chile in Santiago in October.
Costa Rica host Uruguay in a friendly next week.
Sanchez scores as Chile beats 3-2 Paraguay
Arsenal forward Alexis Sanchez scored in the 82nd minute as Chile beat an under-strength Paraguay 3-2 on Saturday, in their first match after winning their first Copa America in July.
Chile took the lead after seven minutes when a defensive blunder from a Paraguayan player allowed Felipe Gutierrez to beat goalie Anthony Silva.
Chile did not seem to miss key midfielder Arturo Vidal, who left Santiago during the week for personal reasons, and dominated the first half against a Paraguay team mostly made up of players from the local league.
Paraguay looked renewed during the second half with Jonathan Fabbro and Jorge Benite scoring within two minutes of each other before Chile's Sanchez and Jorge Valdivia, however, became more influential on the match.
Gutierrez then scored his second goal after a Mauricio Isla cross before Sanchez sealed the win in the final 10 minutes.