Mikel Merino’s goal in the 91st minute was all the Spanish needed to advance to the quarterfinals, where they will play the winner of Monday’s USA-Belgium match.
The goal decided a war of attrition after both teams had failed to live up to the hype of the massive match.
Both teams had good opportunities to score in the opening half. Spain’s Mikel Oyarzabal was through on Portugal’s goal alone early on in the first half but sent his shot wide in the best chance for La Roja.
The best opportunity for Portugal came through Nuno Mendes, whose deflected shot rocketed off the crossbar after cleanly beating Spanish keeper Unai Simón.
There were also great chances for Lamine Yamal, the 18-year-old Spanish star, but nothing that got over the line and into the back of the net before the first half whistle blew.
The second half started much like the first half, as both teams created occasional chances, with most of the action coming from the Spanish.
There ultimately wasn’t a ton of action and was certainly a comedown from the thrilling contests played out a day before.
It took until the 76th minute for the Portuguese to worry Simón off a shot from Bruno Fernandes that came close but sailed just outside the near post.
As time ran down, Portuguese manager Roberto Martinez started to remove some key players for fresh legs but left Ronaldo on the pitch, the 41-year-old superstar who has been his team’s focal point for many years but has been giving declining returns in recent years.
It took until the game was just about to enter injury time for the breakthrough to arrive.
A pass from Rodri to Ferran Torres unlocked the defense, who took a half turn and slid in Mikel Merino unmarked on the Portuguese net.
The midfielder easily fired past Diogo Costa for the opening goal in the 91st minute – enough to give Spain a path to the quarterfinal.
The Portuguese came close to equalizing as the clock ran down as Bernardo Silva’s header had Simón beaten but sailed over the bar.
The loss ends Ronaldo’s sixth World Cup in the Portugal side and it’s difficult to see him returning for another in four years time when the legendary player will be 45 years old.