It was a rematch of the gold medal game in Beijing four years ago, which Brazil won in four sets.
The Americans moved to 2-0 in group play, all but clinching a spot in the quarterfinals.
Hooker had 22 spikes and Larson contributed 16. The set scores were 25-18, 25-17, 22-25, 25-21.
The United States pulled away from an 11-11 tie in the first set to establish the tone for the match and held on after giving the Brazilians hope in the third.
China is also unbeaten in Group B after downing Turkey Monday and the Americans will meet the Chinese Wednesday with the group championship likely at stake. The United States will then finish group play with games against Serbia and Turkey.
The top four from each of the two groups will make it to the quarterfinals.
Russia improved to 2-0 in Group A with a 3-1 decision over the Dominican Republic.
Women's basketball was introduced into the Olympics in 1964 and the Americans have yet to win a gold medal.
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