Linnae Harper, who will be a freshman this fall at Kentucky, had 12 points, eight rebounds and eight assists to help the United States defeat Japan 108-67 and advance to the semifinals of the U19 World Championship in Lithuania.
A'ja Wilson led the Americans with 19 points and 11 rebounds. The U.S. dominated on the glass, outrebounding Japan 70-32.
The Americans (7-0) will play Australia (6-1) on Saturday in the semifinals.
"It's going to be a tough game," said Harper, who is averaging 9.1 points, 5.3 rebounds and 3.7 assists per game. "We played them in an exhibition game. They're really tough. It's going to be a really good game. We can't take anything for granted. We're going to have to play every possession like it's our last and just play hard."
The Australians gave the Americans a close call in the exhibition game on July 12 with the U.S. winning 71-66.
Spain (7-0) and France (6-1) will play in the other semifinal matchup.