The former Baywatch star and '80s pop sensation provided the vocals for the only original track of the movie's Awesome Mix Vol. 2, and he opened up to ET about how the song, "Guardian's Inferno," came about.
"You know, I asked [director] James Gunn why he chose me. He said, 'When I was 8 years old, I saw a show called Knight Rider [and] since that day I've always wanted to meet you and to kind of live by the laws of the Knight Rider," Hasselhoff told ET's Cameron Mathison at the premiere of Guardians of the Galaxy Vol. 2 at the Dolby Theater in Hollywood on Wednesday.
"I'm telling you man, that this show is so much like the Knight Rider. But also more than that," he added. "It was a lot of fun."
While Hasselhoff has had a bit of a career resurgence in the last few years -- often in meta roles that lovingly poke fun at his own past career -- the 64-year-old performer said he took the opportunity to perform a song on the Guardians soundtrack very seriously.
"They brought me in to sing the theme song and it was heavy," he recalled. "I walked into the room and I said, 'You're with the big boys now.' And I just turned it on and I went, 'I can handle it.'"
Hasselhoff wasn't alone in the endeavor to create an original tune that would fit in thematically with the movie's epic soundtrack. Gunn himself joined the singer to provide his voice for the song as well.
"He actually sang the chorus," Hasselhoff said, adding that his own lyrical contribution to the song is "more like a rap."
Hasselhoff's involvement in the project actually makes a lot of sense considering the time frame. Peter Quill, aka Star-Lord (Chris Pratt), is a human who was kidnapped from Earth as a child in 1986.
The soundtracks to both films are supposed to be mixtapes Quill's late mother gave him as a gift, and most of his references are based on pop culture from the '80s. Considering that, Hasselhoff fits right in.
The entire track list for Awesome Mix Vol. 2 was announced on Wednesday, and features such iconic hits as "Mr. Blue Sky" by ELO, "Bring it On Home to Me" by Sam Cooke, and "Surrender" by Cheap Trick, among many other classics.