Remember when John Mayer was the kid in the room? He probably does, and that may goes some way toward explaining why he dropped in for a guest appearance with a younger artist he’s been championing, Alec Benjamin. The not-so-grizzled 41-year-old veteran sat in with the 24-year-old upstart Thursday at the first of his two sold-out shows at the El Rey Theatre in Los Angeles, pairing up for one song by each of them.

The duo first played Benjamin’s single “Death of a Hero,” which, ironically, he has described as being “a story about one of my childhood heroes and how they let me down. It’s about the moment I realized that I wasn’t a kid anymore.” Clearly the song was not written about Mayer, as he went on to say he’d had a poster of the latter up on his wall from the time he was 12 till he was 18 (and half-apologized for not keeping it up longer, but his college dorm wouldn’t allow it). To prove it, Benjamin later posted on Instagram a photo of “the poster I had on my wall of John when I was growing up & have kept all these years,” along with several video clips of their El Rey performance.

The two also played Mayer’s “Slow Dancing in a Burning Room.” “Heroes do exist,” Benjamin declared on social media. “Last night was a dream come true. Thank you @johnmayer for joining me on stage & for inspiring me to make music. You are one of the most talented, humble, & generous human beings i have ever met. I love you & i feel very lucky to have you in my life.”

The love on that social media platform has gone around. Mayer recently had Benjamin as a guest on his Instagram show and called the singer “a young Jedi.”

Benjamin has risen from someone who used to do “parking lot concerts” outside Shawn Mendes shows to a co-writer on Jon Bellion’s debut album to having “I Built a Friend” become a hit via an “America’s Got Talent” sync to an Atlantic debut and largely sold-out tour. His two-night stand at the El Rey wraps up Friday night.