South American supporters, especially, made their presence felt.

More than 1,000 Boca Juniors fans, bedecked in blue and gold, turned Miami Beach into a huge party on Sunday ahead of its opening match, singing club anthems and waving flags in scenes reminiscent of a World Cup carnival.

"Wherever you go, Boca is here," Gaston San Paul, a fan who flew in from Entre Rios in Argentina, told reporters.

"Wherever we are, we do this," he added, referring to the "Banderazo" (flag party), a fan gathering designed to mark territory ahead of a game.

Boca and Real Madrid games were among the early top-selling tickets, according to FIFA, which said that top markets after the United States were Brazil, Argentina and Mexico.

Talk of empty stands was, at least provisionally, dismissed, as well as heightened anxiety in the immigrant-heavy Miami area following recent federal immigration raids.

At the heart of the opening weekend buzz was Messi, whose presence has elevated Inter Miami's profile and guaranteed some global interest in the tournament.