The dynamic duo was joined by Gwyneth Paltrow, who earlier this month (May16) learned of Ryan Wilcox's health battle with leukaemia via a social media campaign on - and his dying wish to meet his favourite stars.

In an effort to make his dream come true, Gwyneth called on Robert and Chris to join her for a trip to Ryan's native San Diego, California, offering up her services as a chauffeur for the road trip from Los Angeles.

On Monday (23May16), Gwyneth posted a photo of her superhero pals walking towards her on an airport tarmac on Instagram, adding the caption, "Let's do this #RyanStrong".

She also shared a short video of them aboard a helicopter overlooking the California landscape below, with all three actors clearly excited to surprise the 18-year-old.

Her social media activity ended with the Iron Man actress posting a snap of Ryan proudly sporting a Captain America shirt and standing in between his personal superheroes.

"Today @ryanwilcox0303 got a little surprise," Gwyneth wrote. "Thank you to the incredible #chrisevans and my better work half @robertdowneyjr for being the men you both are. And thank you to the Wilcox family for your hospitality!"

Chris also took to Twitter to share his experience with Ryan, writing, "Today I got to shake the hand of a true warrior named Ryan Wilcox. He's cooler than I could ever hope to be. Thanks for the hospitality Wilcox family! And a big hug and kiss to two of my favs (faves) @RobertDowneyJr and @GwynethPaltrow for making it happen!"