Rennes: Japan coach Asako Takakura insisted there is more to come from her young team after the Nadeshiko gave their women's World Cup campaign a shot in the arm by beating Scotland 2-1 in Rennes on Friday.
Mana Iwabuchi set the 2011 winners on their way and Yuika Sugasawa converted a penalty as Japan closed on qualifying for the last 16, just four days after a disappointing display in a goalless draw against Argentina.
Takakura's side, ranked seventh in the world, will now go into their final Group D game against England with a chance of topping the section, which would ensure a more favourable draw in the last 16.
"It was a must-win game and, although there were difficult moments, we needed to be aggressive and score goals, and that is what we did," said the coach, whose starting line-up featured six players aged 23 or under, including 19-year-old Jun Endo.
"We were not really able to be ourselves in the first match, but we really had to win this game and I think we were more like ourselves again.
"We have beaten a wonderful Scottish team, but there is room for improvement so we will discuss how we can get better."
Scotland got a goal back late on through substitute Lana Clelland, but they will be disappointed at offering nothing going forward until it was too late, just like in their opening defeat against England.
As they had done in that match, they found themselves 2-0 down at half-time before more than 13,000 fans at Roazhon Park, including a large Scottish contingent and FIFA president Gianni Infantino.
"We obviously conceded two bad goals from mistakes. Take that out of the game and it's much closer," said Scotland coach Shelley Kerr.
"I thought we saw the real Japan today. Their movement was incredible -- we knew it would be, and we tried to set up in a way to stop them. In spells of the game we didn't do that, which sometimes can be understandable because you're playing against world-class players."