Jay Z did NOT pull a fast one on his audience in Greensboro, N.C., Sunday night ... when he brought a 12-year-old boy up on stage who stole the show -- it was all spontaneous.
We spoke with Angela, who took her 12-year-old son Justin to the concert in Charlotte Saturday. She says Justin's dream was to "get noticed" by Hova and he was crushed when he was overlooked as he sat in the 8th row.
Angela says on the ride home they decided to give it one more try, and she bought tickets to the Greensboro concert the next day. She says she was lucky and scored front row seats.
Angela tells us nothing was set up. Justin jumped up with his sign and this time Jigga noticed.
She says after the concert Jay Z was true to his word and took them backstage. They talked for 5 minutes about personal stuff. No numbers were exchanged and Jay said nothing about signing the kid.