"My son Luke has been a fan since he was 3 years old and always has said that he was going to sing with Tim McGraw someday," the mother of Luke Wood, Kendra Wood, who brought her son to the concert Friday night to celebrate his birthday, told PEOPLE.
"He made a simple sign, 'Can I sing with you?' And brought it with us. I was completely shocked when Tim started singing 'Last Dollar (Fly Away)' and motioned for him to come forward. Before I knew it he was whisked onstage, Tim handed him a mic and began singing with Luke," she explained.
The crowd "went wild," as the proud mom whipped out her camera phone. Laughed wood, "I have NO idea how I am going to top this birthday present!"