Paolo Bento’s side needed to avoid defeat and were on course for a victory following Nani’s fifth-minute opener, before two second-half goals from the Americans turned the game on its head. Then, in the 95th minute, substitute Silvestre Varela headed home.
The draw gives Portugal a chance of reaching the knockout rounds following their disastrous 4-0 defeat to Germany in midweek. But on this occasion, rather than wilting, they were completely determined and could hardly have started in better fashion.
In just the fifth minute, USA defender Geoff Cameron failed to deal with a teasing cross from the left wing and the ball fell kindly to Nani at the back post, where the Reds winger took a composed touch before blasting into the roof of the net from six yards.
USA reacted well to falling behind and controlled most of the possession throughout the first half, though Jurgen Klinsmann’s side lacked cutting edge in the final third and former Fulham midfielder Clint Dempsey was the only forward who looked capable of scoring.
As the match meandered towards half-time, it sparked into life and Nani cannoned a shot off the post from 25 yards before Tim Howard produced a superb save to deny Eder, who fired an effort at goal following the United winger’s initial strike.
Michael Bradley should have restored parity in the 54th minute when his shot from Fabian Johnson’s drag-back was blocked off the line by Ricardo Costa, leaving USA coach and former Germany striker Klinsmann to scratch his head in bemusement.