Cystic Fibrosis Sufferer, 9, Becomes 'Iron Boy' For a Day, Gets Support From Robert Downey Jr.

Domenic Pace saved his city by defeating his nemesis, Ultron.

A nine-year-old boy suffering from cystic fibrosis became Iron Man’s accomplice, Iron Boy, for a day and got the blessing of the man behind the mask – Robert Downey Jr.

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The actor posted a special message to Domenic Pace, who became a superhero in Sydney, Australia thanks to the Make-A-Wish Foundation.

Downey, who sent the message as Iron Man’s creator and alter ego, Tony Stark, told the boy: “I don't do this very often, I'm making you an honorary member of the Avengers. I hereby dub thee. Because guess what? Iron Man loves you."

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The actor even tweeted about his new friend.

Sent a very special boy on a top secret mission today. Go get ‘em, Domenic! #IronBoyAU @MakeAWishAust

— Robert Downey Jr (@RobertDowneyJr) February 11, 2016

Pace helped save reporter Hope Joy from his nemesis, Ultron, and his henchmen on Thursday.

Iron Boy traveled around the city by helicopter. The epic final battle came on the steps of the Sydney Opera House, where he defeated the villain and saved the world.

The boy’s bravery earned him a Medal of Valor and an action-packed day that he will remember forever.

Watch: Robert Downey Jr. Gives 'Iron Man' Bionic Arm to Boy with No Arm