Debutants Cape Verde produced one of the biggest World Cup shocks of recent times by holding Spain to a goalless draw in Atlanta.
The third-smallest country in terms of population to qualify for a World Cup, Cape Verde were 67th in Fifa's latest rankings and many expected them to be swept aside by second-ranked Spain in their opening Group H contest.
However, the reigning European champions were laboured in attack for long spells and on the occasions Spain threatened the Cape Verde goal, 40-year-old goalkeeper Vozinha kept them at bay with numerous fine saves.
The introduction of Lamine Yamal as a second-half substitute injected life into his side and the Spain fans inside the stadium, but the Barcelona teenager - making his first appearance for almost eight weeks following his recovery from a hamstring injury - could not produce a decisive moment on his World Cup debut.
Ferran Torres wasted Spain's best chance in the first half, connecting with Marc Cucurella's header back across the six-yard box, but hitting the crossbar under pressure from Vozinha.
Mikel Oyarzabal, scorer of their Euro 2024 winner against England, was denied by a superb block from Shamrock Rovers' Roberto Lopes in the closing moments.
And as Spain pushed late on, they were almost caught out at the other end - but they avoided the ignominy of defeat as defender Diney Borges headed a corner straight at goalkeeper Unai Simon.
Cape Verde reached a first World Cup by finishing top of a group that also included Cameroon, but they were not expected to cause too many problems for a Spain team that has been widely tipped to win the World Cup for a second time.
While there were many heroes in Cape Verde shirts, veteran goalkeeper Vozinha was chief among them and he was almost in tears as he was mobbed by his team-mates shortly after the final whistle.
Vozinha, who plays for Chaves in Portugal's second tier, denied Torres and Aymeric Laporte just before half-time and was always keen to come off his line to collect crosses.
In front of him, Cape Verde kept two rigid lines in defence and for the most part they were able to deal comfortably with Spain's patient build-up play.
They had 27 shots in all, but only seven were on target.
With the eight best third-placed teams moving through to the last 32, the point they have gained against much-fancied Spain will surely give the Blue Sharks huge confidence that they can become the first African debutants to reach the knockout stage of a World Cup since Ghana in 2006.
Spain are no strangers to disappointment in their first match of a World Cup.
They were beaten 1-0 by Switzerland in their 2010 opener before going on to lift the trophy, while defending their title four years later in Brazil, they were thrashed 5-1 by the Netherlands in their first match and failed to make it out of their group.
Two last-16 exits followed in the subsequent World Cups.
Lamine Yamal's return from injury, as well as that of fellow winger Nico Williams, are likely to be the only positives they can conceivably take from a disappointing opening to the 2026 tournament.
While they must improve significantly if they are going to live up to their tag as one of the favourites, their challenge is far from over and they can also look back to the 2022 World Cup for evidence of that.
Argentina were upset by Saudi Arabia in their first group match in Qatar - but recovered to become world champions for a third time.