The U.S. men's boxing team is headed home from an Olympics empty-handed for the first time.

The rest of the world caught and passed the once-dominant American team long before welterweight Errol Spence's uninspiring final effort.

And now the world's best amateur fighters are down to the final days of their quests for all those medals the U.S. won't be winning.

Chinese light flyweight Zou Shiming will attempt to clinch his third Olympic medal when he opens the final day of quarterfinal bouts against Kazakhstan's Birzhan Zhakypov. Ireland's Paddy Barnes, India's Devendro Laishram and Britain captain Tom Stalker are all in action Wednesday in bouts that decide medals.

The U.S. team's fate was decided when Andrey Zamkovoy's arm was raised after an otherwise unmemorable bout. Spence and the U.S. boxers had reached a nadir.

''It's very disappointing for all of us, but we all fought hard and tried,'' said Spence, who couldn't capitalize after his apparent last-gasp loss to India's Krishan Vikas last week was overturned on appeal.

Spence's tentative effort against the more polished Zamkovoy was matched by most of his teammates, who weren't nearly good enough -- or lucky enough in a mostly brutal draw -- to match the nation's boxing pedigree. The Americans went out in a spectacular collapse, losing nine of their last 10 bouts.

U.S. women Marlen Esparza and Claressa Shields already have clinched medals in their sport's debut tournament, but their male teammates are done. The team that won a record 108 medals while sending giants from Cassius Clay to Joe Frazier to Oscar De La Hoya on to Olympic success, and to pro stardom, is at its lowest point.

''The foundation is kind of crumbling a little bit, but we're going to rebuild it,'' U.S. assistant coach Charles Leverette said. ''The support is there, but we have to figure out the best way to help these athletes get back to the top.''