China came into Saturday with a five-gold lead but double 4x400m relay success provided the platform for USA to make up ground.
Allyson Felix became the only American athlete to win 11 track medals as the women cruised to relay gold, while the men coasted to an 18th success as they finished well ahead, the Netherlands a distant second.
Team USA recorded their fourth successive gold in the men’s basketball final, plus there was success for Nelly Korda in the women's golf.
China picked up two golds to take their tally to 38, with Cao Yuan, who became the first athlete to win three different Olympic diving events, and Yang Jian securing a Chinese one-two in the 10m platform. Their other victory came in the women's canoe double 500m sprint.
Early leaders Japan collected a trio of triumphs while the Russian Olympic Committee also secured three golds, Abdulrashid Sadulaev dominating the men's heavyweight freestyle wrestling.
Galal Yafai captured Great Britain's 19th gold with a 4-1 points decision in the men's flyweight boxing final before Joe Choong added another by replicating Kate French's achievement in the men's version of the modern pentathlon.
Australia, who equalled their record medal haul at the Games on Thursday, remain in sixth place, Nicola McDermott's silver making history in the women's high jump with her country's first medal in the event since 1964.