Cheers and groans could be heard from blocks away as the crowd watched the teams battle for the title - and a battle it was, with fans gasping as they saw the slow-motion replay of Dutch midfielder Nigel de Jong landing a kick to the chest of Spain's Xabi Alonso.
"This is soccer, not kung fu," one man said incredulously.
The game was shown on two jumbo screens, with the crowd divided roughly in half. Fans of Spain sat in the grass on one side, while the southern part of the plaza was a sea of orange.
Joachim Arts stood on the Dutch side, rooting for his country with his orange-clad wife, Marie-Julie Arts, and their daughter, 1-year-old Amelie.
Arts is from the Netherlands and said the family had just moved to San Francisco from Pennsylvania two days earlier.
"They're playing a little bit too defensively in my opinion," he said of his team. "Instead of total football it's title football."
To the north, wearing a red and gold soccer jersey, stood Alberto Gracia and his 15-year-old son Yon, who had the Spanish flag draped over his shoulders. The two are vacationing in San Francisco from Spain.
Asked just after halftime how he thought his team was playing, the elder Gracia said in Spanish, "It's difficult in the final."
The plaza was packed to capacity for the game, with food vendors swamped with hungry fans at halftime. People drank from beer bottles wrapped in brown bags, and two women on the Spanish side sipped red wine from glasses.
The plaza has been a magnet for fans throughout the World Cup, with many stopping by on their way to work to catch a glimpse of the early morning games.