Alissa Humphrey's perfect game helped the United States begin heir World Cup title defence in dominant fashion ©WBSC

Alissa Humphrey pitched a four-inning perfect game as the United States began the Under-18 Women's Softball World Cup in Lima in style.

Humphrey allowed no hits and no walks in four innings of work, striking out seven of the 12 batters she faced in a 10-0 win over the Czech Republic at the Villa Maria del Triunfo Sports Complex.

Kinsley Fiedler, Olivia Johnson, Maci Bergeron and Megan Grant all finished with two runs batted in as the game was wrapped up after four innings, owing to the Americans' dominance.

The US are the defending champions.

Chinese Taipei also enjoyed a thumping win.

They beat Colombia 9-0 in the first game of the World Baseball Softball Confederation tournament, buoyed by a six-run first inning.

Colombia only managed one hit so never threatened to get back in the game.

Puerto Rico beat Mexico 2-0, capitalising on poor Mexican defence.

Mexico were charged with four errors and that was the difference.

Keira Bucher pitched seven shutout innings to earn the win, allowing just three hits, but losing pitcher Leanna Marie Garcia Guevara ended with a commendable zero earned runs on her stat sheet.

Hosts Peru claimed a historic win in the last game of the day defeating the Netherlands 3-1.

Peru's win came despite being outhit by their opponents by six to four.