Puerto Rico won a thriller to remain unbeaten at the Women's Softball World Championships ©WBSC

United States, Puerto Rico and hosts Japan all remained unbeaten on the fourth day of competition at the Women's World Softball Championships.

The US defending champions began the day in Group A with an 11-0 thrashing of The Netherlands at the Akitsu Stadium in Narashino City.

This was followed by a later 7-0 win over New Zealand at the same venue.

Puerto Rico also moved on to four wins from four elsewhere in the group, albeit in tougher circumstances, as they edged Chinese Taipei 12-11 in a thrilling duel.

Philippines inflicted further Dutch misery with a 5-4 win over the European side while Mexico thrashed South Africa 8-0.

Mexico are now third in the group with two wins and one defeat while Philippines and Chinese Taipei are each on two victories and two losses.

Australia beat Canada elsewhere today ©Getty Images
Australia beat Canada elsewhere today ©Getty Images

In Group B, hosts Japan are now the only unbeaten team after a 6-0 success over Great Britain at the Zett A. Ball Park in Ichihara City.

Canada's unbeaten run came to an end with a 2-0 loss to Australia.

Both teamS are now locked on three wins and one loss along with China, who beat Venezuela 6-0 today.

Italy lie fifth after an 8-0 thrashing of Botswana. 

Group play is due to continue tomorrow.