NATICK — One fateful October day a century ago during World War I, Private First Class Michael J. Perkins crawled up to a nest of enemy machine gunners that were throwing grenades at his platoon and waited for just the right moment. When the Germans opened the door, he tossed a bomb inside. Then forced his way in and attacked the machine gun crews, and single-handedly forced them to surrender.

The courage that the South Boston war hero displayed on the battlefield was recalled Friday morning, when the Massachusetts National Guard dedicated its armory on Speen Street in his honor.

Among those in attendance at Friday’s dedication ceremony were Gary W. Keefe, the adjutant general of the Massachusetts National Guard; state Representative David Linsky; Colonel Brett Conaway, the brigade commander for the 26th Maneuver Enhancement Brigade; as well as Perkins’s nephew and grand-niece.

“His story is the stuff of legends,’’ Conaway said.

Born in South Boston in 1892, Perkins was a member of the Company D, 101st Infantry Regiment, 26th Yankee Division when he was killed in action on Oct. 27, 1918.

Perkins’s nephew, James Barry, 84, said he grew up hearing about his uncle’s heroic acts on the battlefield.

“I kind of thought [his story] might have been’’ forgotten, Barry said. “But it wasn’t. Apparently it wasn’t.’’

When Conaway spoke at the ceremony, he told the audience about the events that unfolded in France on that day in October, and how Perkins bravely took on the machine gunners by himself.

Conaway said Perkins “voluntarily and alone’’ crawled up a hill to a German “pillbox’’ machine gun emplacement. After throwing the bomb inside the pillbox, he pulled out his trench knife and rushed inside, and fought off the machine gun crews. He killed or wounded several of them, and took about 25 as prisoners.

“He did what he had to do to silence those machine guns,’’ Conaway said. “He was as tough as nails.’’

Within 24 hours after the attack, Perkins was going to get treatment for his wounds when an enemy shell struck the ambulance and killed him on Oct. 27, 1918. Conaway noted in an interview that Perkins wanted to stay on the battlefield but one of his superiors ordered him to go to the ambulance.

Following his death, Perkins was posthumously awarded the Medal of Honor for his courageous actions in combat. A school and an American Legion post were also named in his honor.

In October 1921, The Boston Globe reported that Perkins’s body was brought home from France. His flag-draped casket was placed in the main hall of the Michael J. Perkins American Legion Post in South Boston, and thousands came out to pay their respects to the local war hero.

Huge crowds lined the streets of South Boston and watched as the casket was pulled by a horse-drawn wagon to St. Augustine’s Church. The Globe reported that Governor Channing Cox and Congressman James A. Gallivan were among the many dignitaries who attended the funeral services for Perkins.

Barry said he was excited to learn that the Natick armory would be named after his uncle and was proud to attend the ceremony Friday. His daughter, Jackie Barry, 43, accompanied him to the event.

The dedication ceremony, he said, “couldn’t have been nicer.’’

Emily Sweeney can be reached at esweeney@globe.com. Follow her on Twitter @emilysweeney.