Gonçalo Guedes, Danilo and Bernardo Silva were on top of their games as they took control and the 3-0 scoreline could have been much greater.
The breakthrough came on the half-hour mark when Guedes showed brilliant control, to bring down a long pass from Danilo on the right-wing, as he set up Manuel Fernandes to score only his third goal for Portugal.
Gonçalo Guedes added the second, seven minutes after the interval, before João Mário ended proceedings in the final minute with a crisp strike into the bottom left corner from outside the box.
It was then on to Leiria where debutante Weston McKennie scored an impressive goal to give the USA a deserved lead midway through the first-half.
Portugal improved although the outcome might have been different but for a howler by USA keeper Ethan Horvath. The young shot-stopper somehow allowed Antunes’ cross to squirm underneath him and into the back of the net.
Horvath offered up another chance for Portugal six minutes before the break when Danilo seized onto his poor distribution, but his blushes were spared when the Porto midfielder directed his shot straight into the keeper’s hands.
Gonçalo Paciência (Setúbal) made his full international debut after the break with Gelson making way. Beto, in the home goal, made a spectacular flying save to deny Tyler Adams before he was called upon minutes later to stop an Eric Lichaj effort at his near post.
The resulting corner kick was thudded against the crossbar by Weston McKennie in a manic spell for Portugal. Fernando Santos introduced Bernardo Silva (Manchester City) and Ruben Neves (Wolverhampton Wanderers) to wrestle back control of midfield. Portugal regained some composure and Paciência rattled the woodwork twenty minutes from time. There was still time for Beto to save Portugal yet again as he produced a spectacular kick save to deny Carter-Vickers at point blank range and keep the score deadlocked at 1-1.