The first World Cup final was a repeat of the Olympic final of 1928. In the semifinals, Argentina and Uruguay both defeated their opponents 6–1 (the United States and Yugoslavia respectively). Several incidents occurred prior to this match. There was disagreement over the game ball: both finalists wanted to play with a homegrown football, which forced FIFA to intervene. The conflict was settled by playing the first half with an Argentinian ball and the second half with a ball of Uruguayan origin. Thousands of Argentinian supporters took ferries across the Río de la Plata, the natural border between the two countries, to attend the match. Because of fears of harassment by supporters, the referee for the final was announced just three hours before the start of the game. The referee, Belgian John Langenus, demanded a police escort and a boat to take him out of the country immediately after the final.