Japan into WWC last 16 after 2-0 win over Costa Rica

In an encouraging sign for Ikeda, his Japanese outfit barely got out of second gear against Costa Rica in front of 6992 at Dunedin Stadium.

A two-minute double salvo secured victory and, were it not for the heroics of Costa Rica goalkeeper Daniela Solera, they could have had more.

A well-taken strike from Hikaru Naomoto got the Japanese on their way in the 25th minute before Aoba Fujin followed up shortly afterwards with a tight-angled rocket.

But Ikeda hinted his side, who last won the tournament in 2011 and currently sit second in the group, had more to give as they prepare to face world No.6 Spain.

"The players really set their goals and they came here with a serious goal in mind," Ikeda said through an interpreter.

"We're all looking towards the same goal, they've shown that both on and off the pitch and this unity is a strength of Japan.

"We want to continue fighting as a unit in the next games that come."

Solera stopped things from getting ugly at times but there was nothing she could do to stop her own teammates inviting Japan's opener when Maria Coto slipped and Naomoto fired the loose ball home.

Fujin scampered into the box in the 27th minute and as Solera moved out anticipating a cross the Japanese 19-year-old rifled the ball in at the near post for her side's second.

Japan continued to look for further goals but with victory assured Ikeda began to make changes to rest his troops for the Spanish encounter.

Costa Rica, meanwhile, will face off with Zambia as both sides seek to avoid a winless trip to New Zealand.

Their manager Amelia Valverde refused to discuss her future as she stares at the prospect of two winless World Cups in charge of the national side.

"I have always given 100 per cent and tried to do the most professional job possible," she said.

"We still have a match to play and I don't think this is the right time to answer or to talk about that at the moment."