Underwood teamed with Miranda Lambert to shut down the show with their song "Somethin' Bad" and was clearly surprised when she took fan-voted video of the year.
"It's really hard to believe," Underwood said on stage. "I've been doing this for nine years but every single second of those nine years you guys have been amazing."
Underwood was probably surprised because it looked like it might be shaping up for a double Bryan-FGL win for "That's How We Roll." It was one of the few times Bryan didn't win. Male video of the year winner Blake Shelton bet against himself in the category, wagering that Bryan would win the category. Shelton won for "Doin' What She Likes," and now he'll be doing what Bryan likes.
"I owe Luke an expensive dinner, but that's OK," Shelton joked.
Bryan was a constant fixture early in the awards. He teamed up with his superfriends to kick it off, mashing up "This Is How We Roll," Derulo's "Talk Dirty" and ZZ Top's "La Grange." He took a shot from host Kristen Bell about falling off the stage last week — while wrapped in yellow warning tape.
And he and FGL helped Bell with her monologue, taping a segment poking fun at the Jay Z-Solange Knowles elevator dustup, complete with black-and-white security footage.
He returned to the stage later after winning CMT performance of the year with Lionel Richie for their performance of "Oh No" and "All Night Long" from "2013 CMT Artists of the Year."
"The fact that I have won an award with you is just amazing, buddy," Bryan said from the stage.
"All I can say is, if I'm having this much fun, let's do it again," Richie responded.
Bryan returned to sing his own hit "Play It Again" while he strolled through the audience.
Richie said Bryan is experiencing a run much like his own in the mid-1970s that made him an international star.
"Every once in a while — and it happened to me — there's a moment and time in your career when the forces and stars come together ... and this is Luke's time," Richie said. "I knew it the first time I met him. It really is special. You can see it in his eyes. You can see it in the way he acts. He feels empowered right now and I know that wonderful feeling. And by the way, it's going to happen for a while because he has that genuine personality. "
The Bryan-FGL-Derulo-ZZ Top mega-mashup wasn't the only team up. John Legend, Jennifer Nettles and Hunter Hayes joined together on a countrified version of Legend's hit "All of Me." Eric Church and Lzzy Hale of hard rockers Halestorm turned the volume up to 11 on a version of "That's Damn Rock & Roll" that featured power vocals from Hale and a rap from Church.
Kacey Musgraves and Lee Ann Womack teamed up to salute Alan Jackson with a duet of his song "Livin' on Love" after he was awarded with the first CMT Impact Award. Jackson is celebrating the 25th year of his career.
Keith Urban performed "Cop Car" in a spot-on re-creation of Nashville's legendary The Bluebird Cafe that was surprisingly lifted into the rafters as Urban wrapped up the song. And Little Big Town put on the night's most colorful performance of the new single "Day Drinkin'," beginning on an all-white set before paint cannons turned everything into a rainbow.
The Band Perry won group of the year for "Done" and Cassadee Pope took breakthrough video for "Wasting All These Tears."
Follow AP Music Writer Chris Talbott: http://twitter.com/Chris—Talbott.