For 88 minutes SoFi Stadium hummed with the tension of a contest that refused to be decided, two proud footballing nations trading blows and holding their nerve. Then Mikel Merino arrived. From very close range, with the left foot, he lashed the ball into the top-left corner, and the roar that followed carried Spain into a World Cup semi-final and left Belgium staring at the exit.

It was the cruellest of margins for a Belgian side that had done so much right, that had clawed their way level and looked, for long stretches, entirely worthy of extra time. But quarter-finals do not deal in fairness. They deal in moments, and Spain found the decisive one when it mattered most, in the 88th minute, when legs were heavy and hope was thinning.

The 2-1 scoreline flattered neither side and cheated no one. This was a heavyweight quarter-final that swung this way and that, its rhythm broken by three goals of real quality, its outcome hanging until the final breaths. Spain endure. Belgium go home.

Fabian sets the tone

Spain had begun with the assurance of a team that believes the tournament belongs to them, dictating the tempo and probing for the gaps. The reward came in the 30th minute, and it was struck with authority. Fabián Ruiz, arriving in the centre of the box, met his chance cleanly and drove a right-footed shot high into the middle of the goal, the sort of finish that speaks of a player utterly at ease with the occasion.

It was a goal that felt like the natural conclusion of Spanish pressure rather than a bolt from the blue. They had circled Belgium's box with patience, waiting for the seam to open, and when it did Fabián Ruiz was decisive. The lead was no more than they deserved.

Yet a single goal is a fragile thing, and Spain would soon discover how quickly the ground can shift beneath a leader who grows comfortable. The stadium, bathed in the warmth of a Californian evening, sensed the game was far from settled.

De Ketelaere answers

Belgium's response was swift and it was emphatic. In the 41st minute, Timothy Castagne swung a cross into the danger area and Charles De Ketelaere rose to meet it, powering a header from the centre of the box straight down the middle of the goal. Level, and level on merit, just before the interval.

The timing could hardly have been more damaging to Spanish morale. To concede on the cusp of half-time is to walk to the dressing room with the momentum surrendered, and Belgium seized the psychological ground. De Ketelaere's header was a statement that his side had not travelled to the last eight to be swept aside.

Castagne's delivery deserves its share of the credit, a cross measured to invite the header, and for a spell Belgium wore the look of the team more likely to strike again. The contest had been reset entirely, all the earlier Spanish control counting for nothing on the scoreboard.

Merino has the final word

The second half became a test of will as much as skill, two sides probing and retreating, wary of the mistake that might prove fatal. Chances came and went; the clock ticked toward the additional half-hour that had begun to feel inevitable. Belgium defended with discipline, Spain pressed with mounting urgency, and still the deadlock held.

Then, with 88 minutes gone, the moment Spain had been chasing finally fell. The ball dropped in the six-yard area and Merino was there, sharp and certain, sweeping his left-footed finish into the top-left corner from close range. It was a striker's goal from a midfielder's instinct, the kind of arrival that decides tournaments.

Belgium had no time to fashion a reply. The seconds that remained belonged to Spain, to the men in red who had held their nerve through the anxiety of a game that had slipped from their grasp and then been reclaimed. Merino's strike was worth a place in the last four, and few late goals in this competition will have felt so heavy with consequence.

For Belgium, it was a heartbreak to sit alongside the great near-misses of their recent history, a generation once more denied at the sharp end of a major tournament. They will reflect that they matched Spain for long spells and were beaten by the finest of margins, which is no consolation at all.

What comes next

Spain now stand two matches from the summit, their reputation as one of the tournament's most complete sides reinforced by an evening that demanded resilience as well as class. They were tested here, made to suffer, forced to find an answer when the easy path to extra time beckoned. Champions are often forged in exactly these games, and Spain passed the examination.

The manner of the victory will hearten them. To fall level on the stroke of half-time and still summon a winning goal in the closing minutes speaks of a squad with depth and belief, one capable of altering a game from the bench and the middle of the park alike. A semi-final now awaits, and few will relish the draw that pairs them with this Spain.

Belgium depart with their heads high but their ambitions unfulfilled, a quarter-final defeat that will sting for its narrowness. They came to SoFi Stadium and traded punches with one of the favourites, and for 47 minutes after De Ketelaere's header they carried genuine hope. In the end, one moment of Spanish quality separated the sides, and that is the unforgiving arithmetic of knockout football.