The first game of any tournament is always tough, especially on one of the biggest stages in sports, and that was certainly the case for Samurai Japan in their first game of the Tokyo Olympics.

The hosts struggled to get their bats going against Dominican Republic’s starting pitcher Cristopher Mercedes on Wednesday at Fukushima Azuma Baseball Stadium as the Olympic baseball tournament kicked off. But the offense clicked at just the right time, allowing manager Atsunori Inaba’s squad to eke out a 4-3 victory on a walk-off hit by Hayato Sakamoto in the bottom of the ninth inning.

On a team with veteran ace Masahiro Tanaka, it was Yoshinobu Yamamoto who got the call in the opener and the 22-year-old was superb, giving up no runs and striking out nine across six innings to give his team a chance to win.