The U.S. Marine who became an international inspiration when he crawled across the finish line of the Boston Marathon showed his grit again as he made it to the end of Sunday’s New York City  Marathon on his feet.

Micah Herndon withstood pain and cramps in Boston to honor three friends who were killed in Afghanistan.

MARINE RUNNING BOSTON MARATHON FOR FALLEN COMRADES CRAWLS ACROSS FINISH LINE

He ran the TCS New York City Marathon in 3:05:50, 33 minutes faster than Boston.

Herndon, 31, told ABC News that Sunday’s run was the achievement of a lifetime.

NEW YORK, NEW YORK - NOVEMBER 03: Micah Herndon crosses the finish line at the 2019 TCS New York City Marathon Sunday in New York City. (Photo by Bryan Bedder./NYRR via Getty Images)

"It was a combination of feelings. Really the past seven months just been day-in-day-out living and training and just trying to give my best performance yesterday," Herndon said.

Race organizers invited him to the New York Marathon the day after the Boston Marathon even though his time didn't qualify him. In Boston, Herndon had four miles left to finish the race when his legs gave out, and he ended up crawling on his hands and knees to the finish line.

MARINE WHO CRAWLED ACROSS BOSTON MARATHON FINISH LINE FOR FALLEN COMRADES INVITED TO RUN NYC MARATHON

In Afghanistan, he was in a convoy in 2010 when one of the vehicles hit an IED, killing in Marines Mark Juarez and Matthew Ballard, and Rupert Hamer, a British journalist. He served multiple tours in Afghanistan and Iraq.

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“I run in honor of them. They are not here anymore. I am here, and I am able," Herndon told the Kent Record-Courier in April. "I am lucky to still have all my limbs. I can still be active. I find fuel in the simple idea that I can run. Some cannot."