WASHINGTON: Singer-turned-actor Justin Timberlake made good on his promise to accompany a female corporal to a US Marine Corps ball after she invited him on YouTube and says he was “moved” by the experience.

The Hollywoood star said on his website he was honored and “stoked to be there” with Corporal Kelsey DeSantis, a blonde martial arts competitor who asked Timberlake to Saturday’s event in Richmond, Virginia.

“I knew I would have an evening that I wouldn’t forget... Something I could tell my friends about. What I didn’t know was how moved I would be by the whole experience,” Timberlake wrote on his website over the weekend.

Timberlake said he came away humbled by the dedication of the Marines and enjoyed talking to his date about her passion for training in mixed martial arts.

“It reminded me of how I hear my favorite athletes talk about their sport or, how I hear my favorites among my peers in music and film talk about their craft,” he wrote.

He said they managed to dance a little and that DeSantis kept asking him if he was having a good time.

“She seemed to me to be so humble and honest... Very cool.”

DeSantis, who can be seen in an online video pummeling her bloodied opponent in the ring before being declared the winner in a recent bout, said in a tweet that “the ball was epic! Had a wonderful time.”

The young Marine had issued her video invite after a fellow marine asked Timberlake’s co-star in “Friends with Benefits,” Mila Kunis, to another Marine Corps ball.

“If you can’t go then all I have to say is, ‘Cry Me a River,’“ DeSantis says in a sassy video, referring to a Timberlake hit.

Kunis, who co-starred with Natalie Portman in last year’s sexually-charged hit movie “Black Swan,” accepted the invitation from Marine Sergeant Scott Moore, who tells her in his video from Afghanistan she can call him “Scotty.”

In an interview, Kunis gives him credit for having the courage to ask her to the ball on November 18 in North Carolina.

“The guy’s really ballsy for asking me out.”