Deron Williams and Carmelo Anthony each scored 19 points among six Americans in double figures while Britain's NBA All-Star Luol Deng led all scorers with 25 points at the MEN arena.
The win came 10 days before the US face France in their opening Group A game at the London Olympics. Argentina, Tunisia, Nigeria and Lithuania are also in their section.
The Americans were hugely popular with the Manchester crowd and the names of players such as Kobe Bryant and LeBron James were greeted with louder cheers than those of their British counterparts in the pre-match introductions.
Portland Trailblazers' new signing Joel Freeland put Britain 2-0 ahead but that was the closest the home crowd would come to dreaming of an upset over the world renowned Americans.
A 10-0 run at the end of the first period put the US 33-20 in front and they were 55-37 ahead at half-time before winning comfortably, though the players are taking nothing for granted.
"If we don't come to play, if we're not ready, we can be beat," said Williams, a point guard with the Brooklyn Nets. "Teams could beat us.
"Spain is one of them, Brazil is one of them, Argentina is one of them and we're playing all three teams in warm-up games so hopefully that will help us.
"We realise we have some flaws in our game and we have to sew them up," he added.
Britain coach Chris Finch was unhappy with his team's second-half collapse and blamed mental lapses for a heavy defeat but he warned that the US were not guaranteed to win gold.
"Every game has to be played out, every possession has to be played out," said Finch. "Of course they can be beaten. There are a lot of quality players, a lot of experienced teams in the field.
"The Americans shot the ball extremely well and they have to continue to do so. They're the best team in the tournament, no doubt, but there are a lot of teams who could beat them on any given day."
The skills of the US team were certainly appreciated by the home crowd and the Americans are likely to be not only among the biggest gold medal favourites but also the most popular.
"We love Great Britain, we're brothers and I think the fans here are really appreciative of outstanding basketball," said US coach Mike Krzyzewski.
"The one thing about Great Britain is you appreciate someone who is really good in their sport. There is an etiquette there, a respect, that transcends all sports in Great Britain.
"If an opponent is that good, you acknowledge that and our guys really played hard tonight. It was just a really good night for basketball in Great Britain."
The hosts face Australia, Brazil, China, Spain and the Russian Federation in their Group B games starting on July 29.
