"Stronger" stars Gyllenhaal as Jeff Bauman, a real-life Boston Bombing victim, who lost both his legs in the terror attack and helped police identify the culprits from his hospital bed, then learned how to live life as a double amputee.
Bauman joined the actor on "Ellen," and rooted him on while he tossed a keg, flipped a tire and pulled a golf cart full of ladies across the stage to win the fat check for Bauman's charity of choice, 50 Legs. The organization provides amputees live a happier and healthier life by providing the necessary care and prosthetics that they could not otherwise afford.
DeGeneres also put Gyllenhaal on the spot by asking him to describe the drama, which he also produced, in front of Bauman.
"It's a true story about a guy named Jeff Bauman, who lost both of his legs in the Boston Marathon bombings and through an amazing community and incredible relationships, he got through it and that's the story," the actor said.
"It was a little weird explaining the movie with him, you know," Gyllenhaal added.