After the Canarinho went behind, the Barcelona forward set up the equaliser before scoring a stunning solo effort to put his side on their way to a comfortable victory
The former Santos man scored once and provided an assist, while also having a hand in Brazil's third goal, as the upcoming World Cup hosts recovered from going 1-0 down early on.
Raul Meireles, who had hit the woodwork six minutes earlier with a header, put Portugal in front in the 18th minute after capitalising on a defensive mistake from Maicon.
The Roma right-back attempted to head the ball back to his goalkeeper Julio Cesar, but Fenerbahce midfielder was quick to seize the opportunity - with the former Chelsea man intercepting with a touch, before tucking away the opener.
But Neymar came to the rescue, putting in the corner that found the forehead of Thiago Silva, before dribbling into the box and tucking away into the left-hand corner of the net to put the South Americans in front at half-time.
Just four minutes after the break, Neymar put through left back Maxwell, who crossed for Jo to score his third goal of the week after a brace against Australia.
It was very crisp passing from the Brazilians, who were putting on a show for the American fans and Jo was handed another international goal on a plate after Portugal goalkeeper Rui Patricio was drawn off his line.
Meanwhile, all of Portugal's chances were being wasted by winger Nani, who struck two free-kicks well over the crossbar and had another two audacious shots from range that were not close to bothering Cesar.
The result sees Brazil stay unbeaten in their last three clashes with Portugal.