They were able to defeat Ghana on their final outing in Group G but not by enough, with the United States securing second place as a result of their superior goal difference.
The Portuguese completed their involvement in Brazil having taken four points, three of them coming from their match yesterday. An own goal from Ghana's John Boye after half an hour served to sum up a game which was beset by errors but little quality, despite both sides requiring wins to maintain their interest into the knockout rounds of the competition.
The defender swiped at a cross from Portugual full-back Miguel Veloso, with the ball striking first his knee and then the crossbar before nestling in the back of the net. The farcical nature of the goal was only contributed to by the intervention of referee Nawaf Shukralla, who interrupted a Ghana break inadvertently by blocking a pass.
The African side would improve after the break and Gyan headed his side level after 57 minutes following a delectable cross from Kwadwo Asamoah. Abdul Majeed Waris moments then steered a header wide as Ghana sought a lead.
They were stopped in their tracks by Ronaldo. The forward has struggled with tendonitis in his knee and had been considered a doubt even to play at all. He will contribute nothing further to the finals, ending instead with a sure shot into the net.