Blake Shelton is opening up about the worst decision he’s ever made on “The Voice.”

On Monday’s episode of the popular singing competition, Shelton took a humble dig at himself when addressing teen pop singer Joana Martinez.

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Martinez, who was initially a member of Shelton’s team before defecting to Gwen Stefani’s, performed a rendition of Selena’s “Dreaming of You” that made Shelton come clean about his biggest mistake on the show so far.

“Joana, I can't think of a dumber decision I've made in the history of this show than letting you go from my team. Every week, it's not that you get better, because you've always been great — but you're just coming into your moment on this show,” the “Austin” singer said.

“[Martinez] was actually perfection tonight,” Stefani, Shelton's girlfriend, noted. “I was thinking, ‘Did Blake give me her as a present?’”

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Martinez was in the bottom three during last week’s episode of “The Voice” before rebounding and wowing judges this week.

Though Shelton lost Martinez to his girlfriend’s team, the two have still maintained a courteous relationship amidst the competition. In early November, Shelton gave a speech on the show that moved Stefani to tears.

Stefani, 50, had to choose one of her two remaining team members for Season 17, Destiny Rayne or Rose Short, to move on from the Knockout Rounds to the live show. The former No Doubt singer was having trouble choosing between the two and turned to her fellow coaches, Shelton, John Legend and Kelly Clarkson for advice.

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As he voiced his opinion of the performers, Shelton said, “Rose, I couldn't be happier for you, that you have Gwen as your coach," Shelton, 43, chimed in, per Entertainment Tonight. "Because I've had Gwen as my best friend, and I can see the effect that it has on somebody, the way she helps you to believe in yourself."

“I guess I’m gonna cry over here!” Gwen said.

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Clarkson called the moment “very sweet” and Legend jokingly added that he was surprised that Shelton “actually has a heart!”

Fox News' Tyler McCarthy contributed to this report.