A Michael Jackson impersonator got to celebrate MJ's life by getting close to his family -- meeting Janet Jackson shortly before the 15th anniversary of his passing ... but it cost him a bundle.
Carlo Riley, an MJ tribute artist, tells TMZ ... he finally got to meet Michael's sister after one of her concerts last weekend. Janet had just performed in St. Louis, and Carlo made it to the show.
He says he also decided to fork out an extra $2,000 for the meet-and-greet experience with Janet after the concert.
Carlo says he's been to Janet's concerts in the past and she's pointed him out in the crowd before ... but this was the first time they met face-to-face, and he says she smiled when he thanked her for a great performance.
They snapped the photo and had a very quick exchange -- another notch on Carlo's Jackson belt. He's previously taken pics with Prince, Paris, Katherine, Joseph, Jermaine, Tito, Marlon and Jackie.
Pretty cool ... but the Janet experience is still 2nd to Carlo getting to meet Michael himself in Japan. That was way back in 2007 at a Thriller 25th anniversary party.
Michael's death anniversary was Tuesday, and Carlo says when he saw Janet would be performing just a few days before, he figured it would be a good way to celebrate MJ's legacy.
Riley says Janet didn't say anything about her brother's death during her show, but she did sing "Scream" ... her 1995 collab with the King of Pop.