The United States beat Puerto Rico 8-3 today ©WBSC

Host and defending champions United States defeated Puerto Rico 8-3 as Championship round action began at the Junior Women's Softball World Championship in Clearwater - meaning they are guaranteed a medal at the event.

The Americans held a 4-2 lead after five innings, but scored an emphatic four runs in the sixth to pull clear at the Eddie C. Moore Softball Complex.

China were also comfortable winners today against Australia.

Xiaomin Lu made it home to put the Chinese 1-0 up inside the opening innings.

Neither side managed to post any scores until the final period when Zixuan Dong added a second for China to seal a 2-0 win.

The remaining two Championship round matches required an extra inning to find winners.

Japan and Canada could not be separated in their contest.

The North Americans had taken a 3-0 lead after the third innings, but were quickly caught at 5-5 following the fifth.

Neither side could add to their total, forcing the match into an extra period of play.

The Canadians were up first and edged into a 7-5 lead.

Japan then proved why they are ranked number one in the world as they responded by scoring three runs of their own to steal an 8-7 win.

In today's fourth Championship round match, Chinese Taipei and the Czech Republic were locked at 6-6 following eight innings.

However, Yi-Fan Ho managed to make it home in the additional ninth to seal the win for the Asian country.

Japan defeated Canada in an extra inning ©WBSC
Japan defeated Canada in an extra inning ©WBSC

Competition also began in the placement round with no less than 10 matches today.

Italy defeated New Zealand 7-3 while The Netherlands claimed a 2-0 victory over Great Britain.

Mexico comfortably beat Brazil 10-3 and South Korea thrashed The Bahamas 14-2.

The Koreans then collected a second win of the day after brushing aside Guatemala 9-1.

Ireland made history as they picked up their first victory at a World Championship yesterday.

A second followed within the space of 24 hours as they thrashed Israel 16-1.

Peru also flattened their opponents as they cruised to a 12-1 win over India while Turkey suffered a humiliating 18-0 loss to Argentina inside three innings.

India recovered to narrowly beat South Africa 5-4 to claim their first-ever win at this event and the Philippines also won a close game after just edging the Dominican Republic 5-3.