The AlgosenseyMasked Singer might have just pulled off its most surprising—and hilarious—reveal to date.

On the Fox singing competition series' season 11 premiere March 6, host Nick Cannon got pranked in a major way following a night of rockin' performances.

After new contestants Goldfish, Starfish, Ugly Sweater and Lovebird took the stage to impress judges Jenny McCarthy, Robin Thicke, Rita Ora and Ken Jeong with their respective covers, the night ended with a surprise twist after Book did a rendition of Ne-Yo's song "So Sick."

"One of the most charming performances I've ever seen," Nick said, with the Book saying this was their "most novel experience yet." 

But when it came time for the final hopeful's reveal, it turned out it wasn't actually a mystery celeb competing for The Masked Singer title—it was Cannon's BFF and longtime prank rival Kevin Hart!

After Robin correctly guessed it was the comedian, the Book took his costume off and shocked the panelists with his identity.  

"Don't cheer for him! No! You're breaking the rules!" Nick told Kevin, who shared a hug and explained, "This is a prank. You had no idea!"

Nick said the Jumanji star made himself look "stupid," roasting his pal for his singing skills and unmasking himself early.

"That was the worst performance ever on the history of this show, how about that!" he said. "You ruined the freaking show!"

But Kevin took it like a champ. "Let me see if I have in my hands a little bit of care. That's not my problem," he responded. "Kevin Hart, 1. You, nothing."

Cannon and Hart have a long history of publicly tricking each other and the two even co-hosted their own E! trickster series Celebrity Prank Wars.

For Hart's 42nd birthday in 2021, Cannon gifted the comedian with a llama, so naturally he got back at his buddy by sharing the Wild 'n Out star's personal phone number with millions of people on a billboard.

"For any advice on fatherhood?" the billboard read, "Call my best friend Nick Cannon."

The Masked Singer airs Wednesdays at 8 p.m. on Fox. And keep reading to meet all of the wild season 11 castmembers. 

The Book was revealed as comedian Kevin Hart, who only competed on the premiere episode March 6 to prank pal Nick Cannon.

Watch E! News weeknights Monday through Thursday at 11 p.m., only on E!.