Mikel Merino came off the bench to score an injury-time winner for Spain as they knocked Portugal - and Cristiano Ronaldo - out of the World Cup in a heavyweight last-16 tie in Dallas.

Spain had failed to create clear-cut openings in a poor second half before Ferran Torres played in the Arsenal midfielder, who slotted low past goalkeeper Diogo Costa in the 91st minute.

The 1-0 result was a repeat of their meeting at the same stage in 2010 and sets up a quarter-final tie with either co-hosts United States or Belgium in Los Angeles on Friday, 10 July (20:00 BST).

Portugal's defeat also ends 41-year-old Ronaldo's World Cup career after the superstar confirmed this tournament would be his last.

Spain squandered a gilt-edged chance after just three minutes as Dani Olmo's pass helped Mikel Oyarzabal get behind the defence, but the Real Sociedad striker dragged his effort wide.

Costa then produced a double save to deny Spanish duo Lamine Yamal and Alex Baena in quick succession as La Roja probed for an opener, but it was Portugal who went closest next.

Spain were saved by the woodwork in the 41st minute as Nuno Mendes' venomous left-foot strike took a deflection off Pedro Porro and rattled the crossbar. However, the game remained goalless at the break.

Roberto Martinez's side continued to grow into the game after the break, though Ronaldo cut a frustrated figure up front in a second half that produced little in the way of action in the final third.

Bruno Fernandes hit the side-netting in the 76th minute, while at the other end Olmo's shot from inside the box was blocked by a brave Ruben Dias before the two Spain substitutes combined to produce the match-winning moment.

There has been little to separate Spain and Portugal in their recent meetings.

Heading into this World Cup last-16 tie, six of their previous seven matches had ended in draws after 90 minutes.

And for long periods in Dallas, it appeared extra time and penalties awaited - just like when the sides met in the Nations League final in June 2025, when Portugal won on penalties.

In a goalless first half, it was Spain who produced the better chances, but Portugal went closest to breaking the deadlock through Mendes.

The second half was devoid of much quality but for the decisive moments as the game inched towards extra time.

The European champions caught the Portugal defence napping after Rodri earned them a free-kick and Torres slipped in Merino, who finished into the bottom left corner to begin Spanish celebrations in earnest.

But for Ronaldo - captain, leader and inspiration behind Portugal's Euro 2016 triumph - this is the end of the road, at least on football's grandest stage.

The five-time Champions League winner has said this would be his final World Cup, while, before last week's last-32 game with Croatia in Toronto, Ronaldo's sister stated this tournament would be his "last dance".

The Portugal captain tested Unai Simon - who has now gone 609 minutes without conceding at the World Cup - early in the 12th minute, and almost poked in a knock-back from his Al-Nassr team-mate Joao Felix across the goal in the 37th.

However, it was an underwhelming display from the forward, who stayed on the pitch until the final whistle but registered just 19 touches, with only three of them inside the box.

Spain's 18-year-old Yamal was among those who consoled a crestfallen Ronaldo after the game in a moment that felt symbolic of football's changing of the guard.