ARLINGTON : Spain and old rivals Portugal collide in an enticing World Cup clash in Texas on Monday with the quarter-finals and possibly Cristiano Ronaldo's international career on the line.

The encounter at the air-conditioned home of the NFL's Dallas Cowboys is one of the standout ties of the last 16 and tees up two of the most talented squads in North America.

European champions Spain clicked ominously into gear in the first knockout round by dismantling an efficient but limited Austria 3-0.

A brace from Mikel Oyarzabal and a Pedro Porro header did the damage in a Hollywood style performance in Los Angeles.

Having been held 0-0 by surprise packages Cape Verde to start their title charge, the victory looked much more like the Spain team tipped to challenge for football's biggest prize.

"We played a magnificent match. I am happy because in every aspect we came close to perfection," declared Spain coach Luis de la Fuente.

Ominously for everyone else De la Fuente warned that they can still improve "in every area".

"That is our spirit -- the belief that we haven't hit our ceiling yet," said the 65-year-old, who took Spain to Euros glory two years ago.

Aside from the impressive nature of the win, the Austria win was notable for a man-of-the-match display from Lamine Yamal.

The 18-year-old Barcelona sensation played 85 minutes in California, his longest outing so far at the World Cup following a hamstring injury.

Underlining the confidence coursing through the Spain team, Yamal said: "I want to advance through the rounds and win with Spain."

He added: "We aren't afraid of any team. We are Spain."

"The World Cup starts now," he said.

- 'Fantastic game' -

At the other end of his career is the Portugal skipper Ronaldo, 41, in what will be his final World Cup.

The leading international scorer in men's football has fended off questions about whether he will retire from Portugal duty after the tournament.

After he laboured through a 1-1 draw with the Democratic Republic of Congo in the group phase, the former Real Madrid, Juventus and Manchester United forward scored twice in a 5-0 demolition of Uzbekistan to temporarily silence the doubters.

"I'm back," he said triumphantly afterwards.

After coming second behind Colombia in their group, Roberto Martinez's side beat Croatia 2-1 in the last 32 with Ronaldo scoring from the spot.

With the game heading to extra time, Ronaldo was subbed off for midfielder Ruben Neves.

Martinez, criticised in some quarters for sticking with the ageing talisman no matter what, saw another substitute in replacement centre forward Goncalo Ramos score a dramatic 94th-minute winner.

That sparked more questions to Martinez about the Spaniard's insistence on always preferring Ronaldo to the younger Ramos, queries he batted away.

The veteran looks likely to be in Martinez's starting XI against Spain.

But Spain will be another step up from Croatia, and go into the Texas meeting as favourites to progress.

Recent history is however with Portugal, having twice come back to draw 2-2 in the 2025 Nations League final and then winning on penalties.

"We have great respect for Spain's quality," said Martinez.

"But they are a European team, and we know Spain very well.

"They also know what we are like, so I think it will be a fantastic game... two teams that want the ball, want to look for a goal quickly and create opportunities."