Spain and Portugal announced their joint 2030 World Cup bid as Aymeric Laporte made his first start for Luis Enrique's side after switching from France in a 0-0 draw.
Players from both sides linked arms and wore matching t-shirts to announce the Iberian nations' joint bid for the biggest tournament on the planet before kick off in Madrid. The UK and Ireland will also reportedly make a run for hosting rights.
Laporte has been included in Enrique's squad for Euro 2020 after pledging allegiance to the country following years of being overlooked by Didier Deschamps.
The defender kept Cristiano Ronaldo, Diogo Jota and Joao Felix quiet as Spain and Portugal played out a stalemate in Madrid ahead of this summer's tournament.
In the first international game with fans in attendance in Spain since the onset of the COVID-19 pandemic, the 15,000-strong crowd present thought Spain had fallen behind when Jose Fonte's looping header beat Unai Simon after 23 minutes. However, it was ruled out for a foul on Pau Torres.
A nervy Simon then saw a clearance charged down by Ronaldo. But the ball ricocheted straight back to the Athletic Bilbao stopper.
After struggling early on, the hosts were much better after the restart, with Alvaro Morata and Pablo Sarabia both missing chances.
Portugal were indebted to keeper Rui Patricio, who denied Ferran Torres from close range with two minutes remaining, before Morata hit the bar in stoppage time as Luis Enrique's side pushed for a late winner to no avail.
'We wanted to win, but it wasn't to be. We did some very good stuff and we'll take that away with us,' defender Jose Luis Gaya told Spanish television.
'There's room for improvement, but all sides have things to improve before the tournament.
'Maybe we need to get better at set pieces, which is where Portugal are really strong, but the reality is we had the best chances to win the game.'
Spain face Lithuania in their final warm-up fixture on Tuesday before the Euros kick off next Friday.
Portugal host Israel on Wednesday before they start the defence of their Euro title.