Japan suffered a setback in its preparations for next month's Olympics after a 1-0 home defeat to Tunisia in a friendly Wednesday evening.

Amina Ltaief scored what proved to be the winner when he capitalized on a glaring miss from Japan goalkeeper Hitoshi Sogahata in first-half stoppage time, condemning Masakuni Yamamoto's men to its first defeat in seven matches.

Tunisia went closest to opening the scoring early on at Toyota Stadium when Haykel Guemamdia broke away and rattled Sogahata's woodwork with a fierce shot before Ltaief settled the match after a momentary lapse in concentration from the Kashima Antlers 'keeper.

Sogahata, one of three "over-age" players called up for Athens, fumbled an innocuous cross from Fethi Mercherguri, allowing Ltaief to roll the ball into an empty net.

Japan coach Yamamoto replaced Sogahata after the interval and also brought on strikers Tatsuya Tanaka and Sota Hirayama but the home side was unable to find a way past the Tunisian defense.

"We were unable to get the desired result tonight but I think the match served as a good test and I could see how the players react under pressure," said Yamamoto, who will announce his final 18-man squad for Athens on Friday.