Spain’s Mikel Oyarzabal had the first clear-cut moment in the opening minutes. One-touch football saw the in-form forward collect a pass on the edge of the box with just had the keeper to beat, but he slipped the ball just wide of the right post.
And La Roja kept up the heat. Minutes later, Barcelona star Lamine Yamal’s powerful strike was palmed away by Diogo Costa, only for Alex Baena to line up a curling effort, forcing Costa to make a smart double save.
Portugal had to wait until the 37th minute for goalmouth drama of their own. Joao Felix showed brilliant commitment to steer a fine header towards the net. Spain stopper Unai Simon reacted quickly to get the block, then Cristiano Ronaldo attempted a creative chip over his shoulder, and a recovering Simon leapt to snaffle the instinctive effort.
The opening salvo of the second stanza remained just as tight. Spain were content to keep the ball, defenders dominated the affair and both attacks lacked bravery.
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The best chance came when Dani Olmo found himself in space in the penalty box, but his swift turn-and-shoot was blocked by the Portugal defence.
Spain boss Luis de la Fuente rang the changes and they made their impact felt, as the deadlock was finally broken in the 91st minute. Substitute Mikel Merino latched on to deft pass deep inside the box from Ferran Torres, and he beat Costa with a low, accurate shot into the bottom left corner.
Real Madrid’s Bernado Silva climbed highest in almost the last play of the match to nod a header goalward, but it sailed over the crossbar along with Portugal’s hopes.