The match between Portugal and Spain, played at AT&T Stadium in Arlington, Texas, remained deadlocked for nearly the entire contest. Mikel Merino delivered the decisive breakthrough in second-half stoppage time, with the Spanish midfielder finding the net in the 90+1st minute to send La Roja into the last eight.
England's Anthony Taylor officiated the knockout clash, which was closely contested throughout before Spain's late winner settled the outcome.
With the victory, Spain advance to the quarterfinals, where they will face Belgium — who defeated the USA 4-1 in their Round of 16 match — for a place in the semifinals.