Weston McKennie has become the third-youngest player to score on his debut for the USA as the Americans held Portugal to a 1-1 draw at Estadio Dr Magalhaes Pessoa.
Looking to bounce back from the disappointment of failing to reach next summer's World Cup finals, the US took the lead in the 21st minute when CJ Sapong gained possession on the flank and threaded a pass through to the Schalke 04 midfielder in the area, the youngster applying a composed finish at the near post.
Portugal's equaliser came courtesy of a howler from USA goalkeeper Ethan Horvath, who made a hash of Antunes's hopeful ball into the box, allowing it to slip between his legs and creep into the net.
Both sides plugged for a second goal after the break, but it was the Americans who came closest, McKennie almost completing a debut brace in the 55th minute when he turned a corner kick against the crossbar.
The hosts also struck the woodwork late on through Goncalo Paciencia but neither side could find a winner.