Lakers forward Kyle Kuzma was the final cut as he's dealing with a left ankle injury that prevents him from competing in the tournament.
Kemba Walker, after U.S.'s 78-game winning streak ended: "I think times like this are what’s going to help us come together even more."
The Americans hadn't lost in a major international tournament or exhibition since the 2006 World Championship semifinals against Greece.
Team USA, led by captain Kemba Walker's game-high 23 points, pulled away from Australia in the second half en route to a 102-86 victory.
“We’re NBA players. We’re pretty good at what we do," Celtics forward Jayson Tatum said.
Team USA topped Spain 90-81 in an exhibition game on Friday and showed what fans they should expect in this year's FIBA World Cup.
Kemba Walker has signed for the Boston Celtics, to the delight of his USA team-mates Jayson Tatum, Jaylen Brown and Marcus Smart.
"Not a lot of teams have more than two or three guys out and just working with each other even before the season started," Marcus Smart said
Walker was eligible to receive a $221 million supermax extension over five seasons, but the Hornets offered him just under $160 million.
Jayson Tatum feels he helped convince Kemba Walker to join the Boston Celtics.