Cody Johnson is giving credit to his wife, Brandi Johnson, after his latest CMA Awards victory for album of the year, as he tells PEOPLE that he 'wouldn't be here' without her support.

Country superstar Carrie Underwood, who was not nominated for any Country Music Assn. Awards this year, still made a surprise appearance at the Nashville ceremony to perform with Cody Johnson. The "Before He Cheats" hitmaker joined Johnson onstage to perform their romantic duet "I'm Gonna Love You" in front of a cheering audience inside Bridgestone Arena.