A late goal from Kensuke Nagai gave Japan all three points from their second match of the Olympics against Morocco at the Sports Direct Arena this evening.
Goalscoring chances were hard to come by during the opening 45 minutes as the game descended into a midfield battle.
Japan created the better of the opportunities, but they rarely called Morocco goalkeeper Mohamed Amsif into any telling action.
The Japanese continued dominate proceedings after the restart and this time around they managed to carve out some chances to break the deadlock.
However, striker Yuki Otsu twice put efforts well wide of the target when well placed, while attacker Mami Yamaguchi shot over the bar from the edge of the area.
Just when it looked as though they were going to have to settle for a point, Japan broke the deadlock six minutes from time. Nagai broke free of the Morocco defence before going on to lift the ball over a Amsif in goal.
Zakaria Labyad had a chance to steal a point for Morocco in stoppage time, but his low effort from 12 yards out was blocked.
The victory has seen Japan qualify for the quarter-finals of the competition, while Morocco must beat Spain next time out to stand any chance of reaching the last eight.