The 50-year-old actor is currently shooting in Atlanta for "Captain America: Civil War", where he is reprising his role as Iron Man. He visited the Blaxican food truck with his make-up on, reported E!online.
The Twitter page of the truck posted a picture of owner William Turner and other workers with Robert Downey Jr, where he is seen sporting red scrapes all over his face and a black eye.
"First celebrity on my truck and he is freakn Iron Man! @robertdowneyjr made my day (sic)," Turner tweeted.
The "Sherlock Holmes" actor shared the post, thanking the food truck owner for treating him with scrumptious food.
"Thanx for the grub. Those scrapes were actually from me fighting to get to the front of the line!" he wrote.