'I was just missing a goal,' says Spain's Yamal

"I was just missing a goal or an assist," said the 18-year-old Barcelona sensation, who was named man of the match.

"But as long as we win and advance to the next round, that's what matters," he told journalists in Los Angeles.

Pressed by one reporter on why he seemed glum after a World Cup knockout win, Yamal insisted he was happy inside, even if he didn't show it outwardly.

"I really am happy. That match is over, and now we have to think about the next one," he said.

"I'm very grateful for the affection shown to me in every stadium. It helps me step onto the pitch more motivated," he added.

Yamal, who will turn 19 on July 13, reiterated that his dream is to be a World Cup winner at the final in New Jersey on July 19.

"There's nothing better than the World Cup," he said.

"When a kid dreams about football, they dream of playing in the World Cup. I want to advance through the rounds and win with Spain."

He added: "We aren't afraid of any team. We are Spain. We have to prove it on the pitch."

Yamal did briefly break into a smile when one journalist showed him a video of his three-year-old brother celebrating the victory in the Los Angeles stands.

"It moves me to see my brother, my mother and my friends happy... My brother is like a son to me. I adore him," he said

The comfortable win Thursday was also a fourth straight clean sheet for Spain, who are yet to concede a goal at this World Cup.

"Today we came close to perfection from the 20th minute until the end of the match," said goalkeeper Unai Simon.

"We have to keep maintaining that level to keep advancing through the stages," he said.