A "devastated" Japan head coach Akira Nishino took the blame for the 3-2 loss to Belgium that knocked his team out of the World Cup on Monday, saying he made tactical errors.

The Samurai Blue led 2-0 in the second half at Rostov Arena but allowed the World No. 3 side to snatch a come-from-behind victory in the round of 16.

Goals from Genki Haraguchi and Takashi Inui put the star-studded Belgium team on the verge of elimination, but Japan conceded three times in the last 16 minutes plus injury time to see their dreams of a first quarterfinal berth disappear.

Moments after the loss, the former Japan Football Association technical director admitted he may have allowed Belgium to snatch victory in the fourth minute of added time by failing to adjust his lineup when his team led.

"We were 2-0 up and still the score was reversed. I don't think the players were to blame, I think it was me who might have lost control of the game," the 63-year-old Nishino said.

With Japan looking to score from a corner, Belgium caught the four-time Asian champions off-guard with a length-of-the-field counterattack that culminated in substitute Nacer Chadli's winner.

"When the goal was conceded, I blamed myself, and I question my tactics," Nishino said.

"As for the result I am very disappointed. I am devastated. Yes we took the lead, but we couldn't win."

"When we were 2-0 up, and I didn't change my players, I really wanted to score another goal and we did have opportunities."

"We were to some extent controlling the ball and controlling the game, but at that point, Belgium upped their game when they really had to."

With Japan's oldest-ever World Cup squad falling short of their goal of the quarterfinals, whether or not the tournament could be called a success would depend on how future national teams build on the experience, according to Nishino.

"The players played to the best of their ability, good football, we could show good football on the pitch, but our aim was to go to the next round. So the result, I cannot really call it a success," Nishino said.

"But...whether we can build on this for the next tournament is very important for the Japanese people, so four years from now, we'd like to look back on this tournament and call it a success.