After only managing one goal in its opener, Japan defeated Pakistan 4-0 in the Asian Games men's soccer tournament on Thursday and booked a spot in the last 16.

Yuto Iwasaki scored the first of his two goals in the second minute and scored the last 33 minutes later. The win for national and Olympic team manager Hajime Moriyasu left Japan and Vietnam tied at the top of Group D with two wins each. Moriyasu's team is an under-21 side intended to be the core of the 2020 Tokyo Olympic U-23 team.

"We made a lot of changes, and seizing the victory is a confidence builder," Moriyasu said.

"After the first game, the players came into this game obsessed with scoring goals. It's good we could score four goals. We still made plenty of mistakes, but I want to praise the players for their energy."

Japan's women's team opened its group stage games with a 2-0 win over Thailand.