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"He's a master," exclaimed Fallon after a brutal loss.

Chris Pratt beat Jimmy Fallon at his own game on "The Tonight Show" Thursday.

The actor proved he's one impressive liar when he joined the late-night show to promote his upcoming movie "Jurassic World: Fallen Kingdom" and faced off against him in the game called "Box of Lies."

The rules of the game are simple, and Pratt made the game look easy. There were nine numbered boxes containing some totally outrageous objects only one of them could see at a time. As one contestant described what was in the box, it was up to their opponent to decide whether that person is telling the truth or lying through their teeth.

In round-one, the former "Parks and Rec" star opened a box filled with a diorama of garden gnomes doing yoga. Pratt decided to take the honest route and stumped Fallon in the process. "This is a small diorama of little people, dwarfs. Engaging in ... no, stretching. Yoga and they're all wearing hats," he explained.

Fallen attempted to study his opponent's facial expression, exclaiming, "Chris Pratt… You lie!" But he was wrong, leaving Pratt to call the host "a sucker."

Pratt was not as easily fooled, as Fallon couldn't hold back his laughter during the second round. The 43-year old former "SNL" star said he himself a Jell-O mold with Jeff Goldblum chilling in the middle, which Pratt correctly guessed was the truth.

In the final round, Pratt wound up with a toy dinosaur wearing a pink tutu, tiara, and pink claws on the spinning platform. The actor tried lying this time and did it with ease, tricking Fallon into believing he had a bedazzled skull hidden on his side of the table.

"He's a master," Fallon exclaimed as he named Pratt the winner of the challenge.

Chris' new film, "Jurassic World: Fallen Kingdom," hits theaters June 22.

View Photos Universal First Look at 'Jurassic World: Fallen Kingdom'