Peter Meredith threw a one-hitter and struck out 18 Wednesday night as the United States defeated previously unbeaten Mexico 9-0 in the International Softball Federation World Fastpitch Championships.

Ray Atkinson drove in three runs, two with a fifth-inning double, for the United States, which improved to 7-1 in round-robin play. The U.S. team closes out round-robin play Thursday night against South Korea.Canada remained unscored upon in the tournament with two victories Wednesday. Canada beat the Netherlands 15-0 in five innings and Darren Zack threw a two-hitter to edge Puerto Rico 1-0. Canada (8-0) will play Mexico on Thursday.

In other games Wednesday, Argentina edged Chinese Taipei 1-0; Australia blanked Mariana Islands 12-0; Bahamas shaded Denmark 6-5; Czech Republic routed Russia 20-0 in two innings; Japan beat Botswana 14-0 in five innings; New Zealand shut out Papua New Guinea 13-0 in five innings; Venezuela beat Denmark 5-1; and South Africa downed Israel 3-2 in nine innings.