One of the most remarkable results in World Cup history unfolded in Atlanta on Monday as Cape Verde, appearing at the tournament for the very first time, held European champions Spain to a goalless draw. A nation of just over 500,000 people, ranked 64th in the world, absorbed wave after wave of Spanish pressure and emerged with a point that will be talked about for generations. It was the defining moment of Matchday 5 - and perhaps the defining image of this entire tournament so far.

The result immediately became one of the most discussed sporting moments of the summer, trending across social media from Praia to Lisbon to São Paulo. Those following other live sports events around the world - from china cdbl basketball live to domestic football across Europe - briefly stopped scrolling when the full-time whistle blew in Atlanta. Spain, many analysts' pick to lift the trophy, could not find a way past a side that, on paper at least, had no business sharing a pitch with them on equal terms.

The hero of the hour was unquestionably Vozinha, the 40-year-old Cape Verde goalkeeper who produced a performance of extraordinary composure and quality. He wept at the final whistle, and the reason made the moment all the more poignant: his grandparents, who raised him, died before witnessing this night, and his mother was unable to travel to the United States due to the prohibitive cost of a visa. Coach Bubista resisted singling out individuals in his post-match comments, but nobody in the stadium was in any doubt who had made the difference. Spain manager Luis de la Fuente's decision to keep Lamine Yamal and Nico Williams on the bench for the opening period drew immediate scrutiny; both were introduced but made no decisive impact. The 0-0 scoreline stood.

South American sides struggle to find their footing

If Cape Verde's result was the headline, the broader story of Matchday 5 reinforced a troubling trend for South America. Uruguay, the better team for large stretches of their Group H encounter with Saudi Arabia, were heading for defeat before Maxi Araujo's late equaliser spared them. It was a dramatic rescue, but a draw against Saudi Arabia was not what Uruguay will have had in mind when they arrived in the United States.

The continent's record at this tournament is now a source of genuine concern. Brazil drew with Morocco and were underwhelming. Ecuador lost to Ivory Coast. Paraguay were heavily beaten by the United States. Between four nations, not a single win and - strikingly - not a single moment spent in the lead. According to the context available, this is their worst collective start since 1974. Whether this reflects a structural narrowing of the global quality gap or simply a bad opening week is a question that cannot be answered until all six South American sides have played. Argentina and Lionel Messi begin their title defence against Algeria on Tuesday, and Colombia face Uzbekistan on Wednesday. If both fail to win, the pattern becomes very difficult to dismiss.

Iran's point against New Zealand carries more weight than the scoreline suggests

Iran's 2-2 draw with New Zealand in Group G was, on its surface, an underwhelming result for a team ranked 23rd in the world against opposition ranked 82nd. But context transforms that reading entirely. The Persian Gulf Pro League was suspended in February due to the ongoing war, meaning 17 squad members - six of whom started Monday's match - have not played competitive football in four months. Their training base had to be relocated to Mexico. Several backroom staff were denied visas. The psychological and logistical burden placed on this squad is without precedent in recent World Cup history.

Captain Mehdi Taremi did not dress it up after the final whistle. "It's a bad situation, and we're just tired," he said. "Actually everything is a disaster for us." That Iran came from behind twice and played with enough quality and resolve to earn a point is, in that context, genuinely remarkable. A point could yet prove decisive in securing the team's first-ever place in the knockout rounds. These are athletes competing at an enormous disadvantage through no fault of their own, and they are still competing.

Belgium, Egypt, and what Tuesday brings

Elsewhere on Matchday 5, Belgium avoided what would have been a damaging opening defeat against Egypt in Seattle when substitute Romelu Lukaku - making his customary impact from the bench - forced an equaliser to earn his side a 1-1 draw. It was a performance that raised questions about Belgium's readiness, though a point keeps them level with Egypt at the top of Group G going into the second round of fixtures.

Tuesday's schedule offers no let-up in intrigue. France, two-time finalist at the last two World Cups, make their tournament bow against Senegal - the nation that memorably ended France's reign as world champions in 2002 with a famous group-stage shock. Norway, back at the World Cup for the first time since 1998 and carrying the considerable expectations attached to Erling Haaland, face Iraq. Argentina open their title defence against Algeria. And Jordan, the third debutant at this tournament, face Austria in Santa Clara. Cape Verde's night has set the tone. Anything remains possible.

• Group H: Spain 0-0 Cape Verde
• Group H: Saudi Arabia 1-1 Uruguay
• Group G: Belgium 1-1 Egypt
• Group G: Iran 2-2 New Zealand