Aussies smashed in Olympic softball opener

Australia's softball side have opened the Tokyo Olympics with a crushing 8-1 loss to Japan in Fukushima, where the mercy rule was invoked.

Yu Yamamoto cleared the fence early in the bottom of the fifth innings, boosting her side's lead to seven runs and ending the match in the process.

Home runs from Minori Naito and Yamato Fujita, in the third and fourth innings respectively, gave Japan control of proceedings as empty stands and limited fanfare marked the start of the 2021 Games.

Pitcher Mana Kuwabara and catcher Himeno Miyata, local school students who experienced the region's earthquake in 2011, combined for the ceremonial first pitch.

Australia coach Laing Harrow described the responsibility of launching the Games as a "privilege" for his charges, who have waited for their sport to return to the Olympics since 2008.

The sense of occasion did not spook the Spirit, who played with more composure than the reigning Olympic medallists during the first dig.

An uncharacteristically skittish start from pitcher Yukiko Ueno, whose list of accomplishments include the only seven-inning perfect game in the history of the Olympics, helped the visitors seize momentum.

Ueno walked Stacey Porter then hit batters Taylah Tsitsikronis and Chelsea Forkin.

The blow to Forkin's arm came with bases loaded, meaning Michelle Cox scored the opening run of the tournament.

Japan levelled the score at the end of the first innings, when catcher Tsitsikronis was called for obstruction as Naito scored the first of three runs.

The game remained locked at 1-1 until Naito smashed a two-run homer off Kaia Parnaby.

Australia, who never recovered from that blow, next face Italy in Thursday's late game.