Timberlake in L.A. last month. (Matt Sayles/AP)

Justin Timberlake made good on a promise to escort a Quantico corporal to her Marine Corps Ball in Richmond Saturday night. Kelsey De Santis, a martial-arts trainer, issued a sassy YouTube invitation to Timberlake in July after his “Friends with Benefits” co-star Mila Kunis agreed to a similar date with an Afghanistan-based Marine, triggering a spate of copycat celeb invites. By the looks of things, it was a blissfully paparazzi-free event — thus far, only one photo of Timberlake at the dinner has emerged, via Richmond’s WTVR CBS-6. (Updated 1:30 p.m.: People has a second photo.) You get the impression De Santis, 23, had more than enough swagger for this mission: She told Marine Corps Times last week that she would take her date to the shooting range if he wants, and told Access Hollywood that she would challenge him to a dance-off. Oo-rah!

UPDATE, Monday a.m.: On his blog this morning, Timberlake called the gala “one of the most moving evenings I’ve ever had,” praising the humbleness and awesomeness of the folks in uniform. Especially De Santis, who made an effort to make sure he was enjoying himself. “I have to tell you, it’s not every day that I meet a 23 year old girl and she’s more worried about if I’m having fun or if I’m comfortable! It hit me all of a sudden that these were the type of people that look after us and our freedom... Humble, concerned for others before themselves... This was the type of person our Marine Corps was building. I was really blown away.” Read more.

Read earlier: Justin Timberlake and Mila Kunis: Still on for Marine Corps Balls?, 11/6/11

Celebrity guests at Marine Corps Balls: Do the Few and the Proud know what they’re getting into?, 7/19/11

View Photo Gallery: The singer and actor has transitioned from boy band member to an acting career with frequent appearances on “SNL” and major productions such as “The Social Network.”