9-Year-Old With Cystic Fibrosis Becomes 'Iron Boy' for the Day in Australia

— -- A 9-year-old boy with cystic fibrosis saw his wish to be Iron Man come true when the entire city of Sydney, Australia, got behind him and turned him into "Iron Boy" for the day.

Domenic Pace even got a shout-out from Iron Man himself, Robert Downey, Jr., who played the superhero on the big screen.

The actor tweeted about Pace’s "top secret mission" on Wednesday.

Domenic’s mom told Make-A-Wish Australia, which coordinated Domenic’s adventure, that he would only answer to “Tony” (Tony Stark, or Iron Man) starting at a young age.

On Wednesday, Domenic was whisked to New South Wales police headquarters via a helicopter and outfitted in an Iron Boy costume.

He was then taken to a nearby island to help rescue a Make-A-Wish news reporter who had “been kidnapped by Ultron’s henchmen,” according to Make-A-Wish Australia.

Domenic, as Iron Boy, then traveled back to Sydney, where he defeated Ultron on the steps of the iconic Sydney Opera House.

In an epic conclusion to the day, Downey recorded a special video message for Domenic and made him an honorary member of the Avengers.

News outlets throughout Australia and the world tweeted about Domenic's day, which was reminiscent of the day in the U.S. nearly two years ago when San Francisco transformed into Gotham City to fulfill a then-5-year-old boy's wish to be Batman for a day.