'The Voice': Kelly Clarkson, Adam Levine teams face off in the first ever Cross Battles

It was a historic night on "The Voice."

The new live Cross Battles debuted on the singing competition Monday, where coaches picked one of their artists in real time to compete against another team's artist. (Think school yard pick, singing edition.)

"The stakes are higher than ever because coaches can see their whole time taken out during this round," host Carson Daly said, saying that for the first time, the coaches can enter the Top 24 with uneven numbers of contestants.

One of the most unforgettable battles of the night took place between Team Kelly Clarkson and Team Adam Levine. Clarkson picked Matthew Johnson, 26, and challenged Levine, who picked Domenic Haynes, 18, to face off in a soulful showdown. 

"I’m going for Mr. T," said Clarkson, referring to Levine's new Mohawk. "Come on, Adam."

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Johnson belted out Smokey Robinson's "Who's Lovin' You," while Haynes poured his heart into Etta James' "Damn Your Eyes," locking eyes with Clarkson in her second serenade in as many weeks.  

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"The way you were singing to Kelly, I almost went over there and poked her eyes out," Blake Shelton said. Clarkson didn't back down, saying she was staring back at Haynes like the "dragon lady on 'Game of Thrones.'"

Despite fraternizing with the enemy during her serenade, Clarkson backed Johnson: "I’m so impressed by you. … I’m such a fan."

Levine endorsed Haynes, asking viewers to vote for him. "You are one of the most honest, raw, emotional, powerful singers this show has ever seen," Levine said. 

"I wanted you both on my team," John Legend added. "America, you have a tough choice."

Both singers' fates now rest in the hands of viewers, who will decide who moves on by voting on "The Voice" app or at NBC.com/VoiceVote. The winners of every Cross Battle will be revealed Tuesday nights on the results show.

Each coach gets one save and one steal, so anything can happen.