The attendance at Marvel Stadium, which normally hosts soccer, cricket and Australian rules football, was 51,218, billed as the largest crowd ever to watch a basketball game in Australia. The stadium was transformed into a makeshift basketball arena for two games against the Americans before the World Cup starts this month in China.
After Australia briefly took the lead at 45-44 early in the second half, the Americans scored 13 unanswered points, including three straight 3-pointers by Turner, Harrison Barnes and Donovan Mitchell, to go up 57-45.
"The way we bounced back in the second half shows the character of this team,'' Mitchell said. "We played in front of 55,000 people -- there's going to be nerves, guys are going to be geeked up and ready to go. But once we settled down and started playing our basketball, we were in good shape.''
Walker was one the keys for the second-half resurgence for the Americans, scoring 21 of his 23 points after halftime.
"I'm one of the leaders of this team, so it's important for me to set that tone,'' the Celtics guard said.
The roof of Marvel Stadium was closed for the game and a raised basketball court was dropped in the middle of the field, surrounded by hundreds of white chairs, more than 20 rows deep, for fans who paid for floor seating.
"Everyone came out tonight,'' Mills said. "Fans being able to show their full support, it's really cool, really good to see and hopefully we keep this up for years to come.''
Despite the huge crowd, Australian media reported that some fans were issued refunds because they bought tickets based on promotional materials depicting Stephen Curry and LeBron James. Neither is on the team.
Australia was also without its biggest star, Ben Simmons, who has opted not to play in the World Cup. Still, the Boomers' starting lineup included four NBA players: Mills, Aron Baynes, Joe Ingles and Matthew Dellavedova.
Both teams needed time to adapt to the unusual conditions in the cavernous stadium. Walker tossed up an air ball with the first shot of the game, while Baynes missed his first two free throws for the Boomers.
The crowd was subdued as well, producing only a smattering of applause for American baskets. However, cheers erupted when the Boomers erased the U.S. lead before halftime on back-to-back 3-pointers by Goulding and six straight points by Mills.
The win was the 78th in a row in major international exhibitions and competition for the U.S. national team, a streak that started with the bronze-medal game of the 2006 world championships. It encompasses gold-medal runs at the 2010 and 2014 World Cups, the Olympics in 2008, 2012 and 2016, and the FIBA Americas tournament in 2007.
It also made the U.S. 2-0 under coach Gregg Popovich, after last weekend's exhibition win in California over Spain.
Boston's Marcus Smart, who is still working his way back from a calf injury that popped up about two weeks ago during training camp in Las Vegas, did not play. San Antonio's Derrick White also didn't play for the U.S. until the final minutes. ... It was the first meeting between the national teams since the Americans won 98-88 at the 2016 Rio de Janeiro Olympics on their way to a gold medal.
Australia: Actor Russell Crowe, who spends most of his time living in Australia, was part of the massive crowd. ... In a sight that NBA fans are used to, Dellavedova dived on the floor for loose balls three times in the game's first three minutes, including on the opening tap. ... Mills gave Popovich, his longtime coach in San Antonio, a massive hug courtside just before the game started.
Jayson Tatum got knocked over by a defender in the third quarter and tumbled backward somewhat awkwardly, the back of his head falling into Walker's knee. Tatum was shaken up briefly but remained in the game.
The teams meet again in Melbourne on Saturday.