The city of Sydney, Australia, is safe today thanks to the efforts of a brave 9-year-old hero.

With the help of Make-A-Wish Foundation, Domenic Pace was called to action by the New South Wales Police Commissioner Andrew Scipione to become Iron Boy. Scipione needed Iron Boy's help to save the city and a kidnapped reporter from the villain Ultron.

"Iron Boy, we need your help," Scipione said in a video message to Pace, on Yahoo News Australia. "Make-A-Wish reporter Hope Joy has been kidnapped. Officers have confirmed that Clark Island has been overtaken by Ultron's henchmen and Hope Joy is being held captive."

After being picked up in a helicopter and briefed by police, he bravely battled evil henchmen, saved Hope Joy and defeated Ultron in front of the Sydney Opera House.

Robert Downey Jr., in character as Tony Stark, the real Iron Man, recorded a video message for Domenic to congratulate him and make him an honorary member of The Avengers.

"I hear you've had quite the day," Downey said in the video. "It's hard work saving the world, isn't it?"

He wished the boy the best and told him that Iron Man loved him.

According to Yahoo News, Scipione thanked Iron Boy on behalf of the police department and the citizens of Sydney and expressed his gratitude for being able to play a part.

"It can't be easy dealing with an illness like his and we feel privileged to be able to work with Make-A-Wish Australia to ensure his wish to be a famous superhero came true," Scipione said in the article.

Many others took to social media to show their support for Domenic using the #IronBoyAu hashtag.

According to the Make-A-Wish Australia website, Domenic has suffered from cystic fibrosis his whole life and has to have "hours of treatment every week."

In a video from Make-A-Wish, Domenic's mother described him as a caring child who is "more interested in helping children and other people rather than playing with toys."

She explained to Make-A-Wish her son's interest in Iron Man.

"From a young age he would only answer to Tony," she said on the site, referring to Tony Stark, Iron Man's real identity. "I guess the final straw was when he just sat up at the dinner table and said 'I am Iron Boy!'"

A similar wish was made true by Make-A-Wish when 5-year-old Miles Scott became "Batkid" in San Francisco. He also fought crime and saved a "damsel in distress."