Bill Iffrig, a 78-year-old running his third Boston Marathon, was knocked down by the first bomb blast at the end of the finish, but got up to finish the race.
Though he fell to his knees by the force of the blast, stewards helped him to his feet and he walked the short remaining distance to the finish line, as well as a further half a mile to his hotel.
"I got down to within 15 feet of the finish apron and just tremendous explosion," he told CNN.
"The shockwaves hit my whole body and my legs started jittering around. I knew I was going down.
"It was only 5 feet away from me. It was really loud."
Iffrig added that despite the shock, it never occurred to him not to finish the marathon.
"After you've run 26 miles, you're not going to stop there," he said.
In the midst of the horrifying stories emerging from the finish line of the Boston Marathon, Iffrig’s heart-warming moment of bravery has been picked up by American news.
His son, Mark, had been tracking his father’s progress in the race online.
"It's horrible. He said it was quite a concussive blast. He was a little dazed. Someone helped him up," said Mark Iffrig. "He was only about 10 feet from the finish line."
Iffrig paid tribute to his father, describing him as an avid runner.
"He's a hell of a runner," he said. "He's run a lot and he's fast."
- Athletics, Track & Field
- Boston Marathon