The decisive moment came in the 88th minute when substitute Mikel Merino converted from close range after Belgium goalkeeper Senne Lammens failed to hold the ball. The victory sends Spain into the last four, where they will face France on Tuesday, keeping alive hopes of another World Cup title.
The match briefly swung back into the balance after Belgium equalised, but Spain maintained pressure throughout the closing stages. Merino, who also scored the winner against Portugal in the round of 16, once again proved decisive from the bench.
In Brussels, Belgian supporters applauded their team despite the defeat, while many admitted the injury to their first-choice goalkeeper had changed the course of the contest.
Spain now heads into the semi-final with momentum after back-to-back knockout victories decided by Merino's late interventions.
