"Dreams do come true," Key wrote on Twitter.
It is indeed a dream for most everybody who has performed sketch comedy to one day grace the stage of NBC's long-running comedic institution, which is in the home stretch of its 46th season.
For Key, who was born in Southfield and raised in Detroit, it's the culmination of the 50-year-old's long journey as a performer, which has included six seasons of Fox's one-time "SNL" rival "MADtv" and five seasons of Comedy Central's "Key & Peele" (with his "MADtv" co-star, Jordan Peele) and which began in the city as a member of the now-defunct Second City Detroit troupe and a founder of Hamtramck's Planet Ant theater.