Yuta Watanabe (R) of Japan shoots past Khris Middleton of the United States during the group E match between Japan and the United States at the 2019 FIBA World Cup in Shanghai, east China, on Sept. 5, 2019. (Xinhua/Chen Fei)

SHANGHAI, Sept. 5 (Xinhua) -- The United States remained unbeaten in Group E after an easy 98-45 victory over Japan at the 2019 FIBA World Cup here on Thursday.

The Americans lived up to their pre-tournament billing as favorites, starting with a 13-0 run before Yuta Watanabe finally opening the scoring for Japan with two free throws.

They had killed the game off by half-time, leading 56-23. But the defending champions did not lose focus, with a solid defense limiting Japan to only eight points in the third quarter, four of which came from NBA rookie Rui Hachimura.

Jaylen Brown scored a game-high 20 points, while teammate Kemba Walker added 15 points. Yudai Baba had 18 points, making him the only Japanese to score double digits.

"We did a good job with respect to the game and respecting our opponents. The consistency is necessary. We need to improve our execution and consistency. And what we have to do as a team is to be successful," said USA coach Gregg Popovich.

"The Dream Team didn't give us an option in the game from the first quarter. Their defense was very good and frustrated our offense. We lost our confidence for the rest of the game. We wish to play better and win the next game," said Japanese coach Julio Lamas.

The United States will play Greece and Brazil in the second round which starts on September 7.

"Every team is different, you have to figure out how to get better, and that makes it very interesting," Popovich added.