Jamie Foxx will be forever grateful to Robert Downey Jr., after the Iron Man star showed up to his daughter's fifth birthday party as a surprise guest.

The Django Unchained star asked his The Soloist co-star to show up at his kid's bash after he overheard her telling friends she knew Downey's Iron Man alter-ego Tony Stark because he was close to her dad.

Foxx tells U.S. Tv host Katie Couric, "We had an Iron Man-themed party and... it was just a shot in the dark. I text Robert Downey, Jr. and I'm like, 'Hey, listen man, my daughter is turning five, and (is having) the Iron Man theme (at her party).'

"He shows up just before the party, brings like a whole big thing of Iron Man toys and passed it out to all the kids and then I was, like, trying to rush it because I thought he was in a hurry and he was like, 'Dude, here's the deal, I'm here, don't worry about it...' So he hung out and, to this day, I'm indebted to that dude."