The USA, looking for an encouraging display as they prepare for a crucial Confederations Cup play-off against Mexico next month, were run ragged as Brazil turned on the style at the Gillette Stadium in Foxborough.
The scoreline matched the worst ever suffered by the Americans under Klinsmann, who were beaten 4-1 by Brazil in 2012 and 4-1 by Ireland in 2014.
Brazil, who face a daunting opening to their 2018 World Cup qualifying campaign away to Chile next month, were always in control.
Substitute Danny Williams scored a late consolation for the Americans, lashing home a 30-yard screamer in the 90th minute.
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The South Americans dominated a one-sided first half, threatening to run riot against an experimental United States formation featuring Alejandro Bedoya playing in an unfamiliar defensive midfield role.
The Brazilians swept forward confidently and did not have long to wait until their early superiority was rewarded with the first goal.
Chelsea star Willian burst clear of two American defenders down the right flank and curled a looping cross beyond US keeper Brad Guzan.