Wales Sevens coach Gareth Williams admitted his team had missed their opportunity as they were denied a chance to bid for a repeat of their 2009 Rugby World Cup Sevens triumph.
Wales won their opening match against Zimbabwe on Saturday, 33-12, but were then well beaten by the hosts USA, 35-0.
It means they missed out on a chance to play England in the last eight and they must now concentrate on the Challenge Cup instead.
“We started the game well against USA in a great atmosphere,” said Williams.
“We implemented what we wanted to early on, but we couldn’t make the decisive break to score when we had them under pressure.
“I can’t fault the effort and the ambition of the boys, but USA are a good side who will be tough to beat on their home patch.”
The score may not have reflected the flow of the game, but Williams highlighted the impact of America’s household names, such as superstars Perry Baker and Carlin Isles.
“When you have game breakers as they do, the score can accelerate late on in the match.”
Wales now meet Samoa in the Challenge quarter-final at 23:10 BST.