Luis Abram was the hero as Peru exacted some revenge over Brazil with a 1-0 victory in a rematch of the Copa America final.
Brazil claimed their ninth Copa America title by beating Peru 3-1 in South America's showpiece tournament decider in July.
But defender Abram's 85th-minute header saw Peru past Brazil in Los Angeles on Tuesday, while condemning the Selecao to their first defeat since the 2018 World Cup.
Neymar started on the bench as Tite made four changes to his line-up that drew 2-2 against Colombia, with David Neres, Eder Militao and Allan coming in for the PSG star, Dani Alves, Thiago Silva and Arthur.
It was a scrappy match on a pitch that still showed the marks of American football in Los Angeles, where NFL franchise the Rams and the NCAA's USC Trojans are tenants.
While there was plenty of energy and endeavour from Peru, chances were few and far between in the first half – Edison Flores' volley in the 23rd minute the closest either team went to breaking the deadlock.
After Neres went down inside the area under a risky challenge from captain Luis Advincula amid appeals for a penalty, Flores then produced an instinctive volley to force Brazil goalkeeper Ederson into a save.
There was a nasty clash of heads between Brazil team-mates Casemiro and Neres just past the half-hour mark, but both players managed to play on.
Pedro Gallese came to Peru's rescue four minutes into the second half. Richarlison played a delightful throughball to Allan but the goalkeeper was quick off his mark to deny the Brazil midfielder his first international goal.
A drilled effort from Philippe Coutinho caused problems for Gallese just past the hour-mark before Neymar's introduction, and while the latter provided some spark, there was to be no breakthrough for Brazil.
Just as the match looked to be petering out for a draw, a delightful free-kick from Yoshimar Yotun picked out Abram, whose deft touch beat Ederson and found the back of the net.
What does it mean? Peru end Brazil's unbeaten run
Since losing to Belgium in the World Cup quarter-finals last year, Brazil had gone 17 matches without defeat. However, that impressive run came to a shock end in LA.
Abram opens account in style
Making his 17th appearance, Abram emerged the unlikely hero for Peru. His late header not only silenced Brazil but saw the 23-year-old celebrate his first international goal.
Neymar poised for Selecao century
After marking his first appearance back with a goal and an assist against Colombia last time out, Neymar was a second-half substitute in LA. The 27-year-old's appearance, though, was his 99th on the international stage – moving him clear of Ronaldo and Djalma Santos for seventh in the all-time Brazil standings, still well adrift of Cafu's appearance record of 142.
Brazil will return to action in October with a friendly against Thailand in Singapore and another fixture that is yet to be determined. Peru, meanwhile, are set to take on Uruguay in a pair of friendlies next month.