Japan's Under-23s beat Vietnam 2-0 on Thursday in their final warmup for next week's Under-23 Asian Championship, the continent's final qualifying competition for this summer's Rio de Janeiro Olympics.

Fagiano Okayama loanee Yuta Toyokawa, a late addition to the squad, and JEF United Chiba striker Ado Onaiu both scored in the first half of the game played behind closed doors in Doha, but Japan coach Makoto Teguramori revealed it was not all plain sailing.

"We had good shape at the start of the game and were able to score goals but we also got ourselves in some dangerous situations in the second half," he said.