Shohei Ohtani belted a grand slam and added an RBI single during a 10-run second inning, fueling defending champion Japan to a 13-0 victory over Taiwan on Friday in a pool play game during the World Baseball Classic in Tokyo.

The 10 runs were the most scored in an inning in WBC history.

Ohtani, who ripped a double on the first pitch of the game, fell a triple shy of the cycle to pace Japan's 13-hit attack in the opener of round-robin play. The Japanese (1-0) are competing with Australia (2-0), Korea (1-0), Czechia (0-2) and Taiwan (0-2) in Group C.

Taiwan mustered just one hit -- a single by Tampa Bay Rays second baseman Yu Chang to lead off the sixth inning -- and has been shut out in both of its games in the tournament.

The game ended after seven innings due to the tournament's mercy rule.

The top two teams from each of the four pools will advance to the quarterfinals, which will be split between Miami and Houston. The semifinals on March 15 and 16 as well as the final on March 17 will be contested in Miami.

Playing in front of his home crowd, Ohtani deposited a 2-1 pitch from Hao-Chun Cheng over the wall in right-center field to open the scoring with his first grand slam in WBC play. The Los Angeles Dodgers superstar and reigning WBC tournament MVP then watched as Masataka Yoshida of the Boston Red Sox ripped a triple, Chicago White Sox acquisition Munetaka Murakami drove in a run with an infield single, Sosuke Genda had his first two-run base hit of the day and Kenya Wakatsuki added an RBI single in the second.

Ohtani capped the seven-hit inning by scoring Genda with a line-drive single to right field.

Kazuma Okamoto had an RBI single and Genda added another two-run single up the middle in the third inning.

The offense was more than enough for the Dodgers' Yoshinobu Yamamoto, who allowed three walks and struck out two batters over 2 2/3 innings. Shoma Fujihira worked out of a bases-loaded jam in the third inning.

Stuart Fairchild, whose mother, Mimi, is Taiwanese, nearly put Taiwan on the scoreboard in the fifth inning. The drive to left field by Fairchild, who is in the Cleveland Guardians organization, sailed just outside of the foul pole.