Japan begun their bid to retain the Under-23 Baseball World Cup title by thrashing South Africa in Barranquilla today ©WBSC

Japan begun their bid to retain the Under-23 Baseball World Cup title by thrashing South Africa in Barranquilla today.

Left fielder Ryosuke Kishisato hit the first home run of the tournament with the Japanese going onto register a 13-0 win at the Edgar Renteria Baseball Stadium.

Right fielder Ukyo Shuto and clean-up hitter Yasuhito Uchida, the team captain, also managed home runs in the bottom of the fifth and sixth innings respectively.

It puts them joint top of Group A along with hosts Colombia and Mexico.

Colombia beat The Netherlands 9-5 today, while Mexico defeated Chinese Taipei 2-1.

South Korea made a winning start to their Group B campaign ©WBSC
South Korea made a winning start to their Group B campaign ©WBSC

In Group B, 2016 bronze medallists South Korea started their campaign with a 14-3 victory over Czech Republic at the Estadio de Beisbol 18 de Junio in Montería.

There were also wins for the Dominican Republic and Venezuela with the former overcoming Puerto Rico 9-6 and the latter beating 2016 runners-up Australia 4-2.

Round-robin action in Colombia is due to continue tomorrow.

The Group A schedule is made up of matches between Japan and Chinese Taipei, Mexico and The Netherlands, and Colombia and South Africa.

In Group B, Australia face Czech Republic, the Dominican Republic meet South Korea and Venezuela go up against Puerto Rico.