TOKYO, July 21 (Xinhua) -- Japan and the United States, softball favorites to claim a gold medal, beat their rivals respectively in Tokyo Olympics openers at the Fukushima Azuma Baseball Stadium on Wednesday.

Host and reigning champion Japan topped another strong squad Australia 8-1 in the opening round, the very first match to start off the Games.

Meanwhile, American pitcher Osterman Cat stuck out nine in the first six innings to defeat Italy 2-0. She claimed gold in Athens 2004 and silver in Beijing 2008.

Later in another contest, Canada beat Mexico 4-0. It is the first time for Mexico to qualify for the Olympic softball, while Canada is the only team that has participated in all of the past four Summer Olympics yet without winning a medal.

"We have one more game here at Fukushima tomorrow. I want to head into the game well prepared and win again," said Japanese captain Yamada Eri, who won the gold medal at the 2008 Beijing Olympics.

Her comment was echoed by third base Yamamoto Yu. On the outlook going forward, she said "just to focus on one game at a time."

"She (Ueno Yukiko) was pitching neatly and with caution in the first. She allowed a run there, but I knew she was going to quickly adjust. And she did adjust," said Yamamoto.

In the 2008 Beijing Games, Japan stunned the world by defeating the USA 3-1, putting an end to a 22 win streak of the US team.

It has been 13 years since softball last appeared on the program for the Summer Olympics. The game was first introduced to Summer Olympics in Atlanta 1996 and voted out of the program in 2012 and 2016. After its temporary appearance in Tokyo, softball will be again dropped in Paris 2024.

Host Japan is seeking a second Olympic gold medal, but its strong rival USA is also seeking revenge.

On July 22, the United States will compete against Canada and Japan against Mexico at Fukushima Azuma Baseball Stadium. The first two days of contests take place in Fukushima which was struck by a 2011 nuclear accident caused by tsunami, and the rest of the matches that last until July 27 will be held at Yokohama baseball stadium.