The competition is getting serious.

Kelsea Ballerini, Michael Bublé, Adam Levine, and John Legend on ‘The Voice’. Photo: Tyler Golden/NBC

The first night of Battles on The Voice featured some big moves, most notably John Legend and Adam Levine whipping out one of their most powerful tools as coaches: the save. Each of them, including Kelsea Ballerini and Michael Bublé, has only one to use to rescue someone from their team who has lost a showdown with another team member.

Legend used the rare move on New Orleans native Nell Simmons, 40, after she went head-to-head with another of his singers, Olivia Kuper Harris, a 34-year-old from Dallas. They sang Roberta Flack’s “Feel Like Makin’ Love” and both women killed it.

Afterward, Bublé complimented them both: “You guys transported us into another era, and I loved it.”

And Levine lamented that he hadn’t turned for Simmons on her Blind Audition. “You guys are so strong,” the Maroon 5 frontman said. “But the big revelation here, I think, is Nell.… We were a hundred percent incorrect” not to turn their big red chairs for her.

So when Legend made the close call in favor of Kuper Harris, Levine pounced and attempted to steal Simmons.

“I really should’ve turned for you originally,” Levine said. “That was my big takeaway, when I heard you sing today, ’cause when you took your moment, I was like, ‘Damn!’ I just think you’re really special, and I think you were overlooked, and I don’t want that to happen again.”

Legend seemed like he was having the kind of regret love songs are written about, and he used his save. Oh, how the tables had turned in just a few seconds. Now it was all up to Simmons to decide which team she was on.

He pleaded with her: “I’ve heard and seen your talent from the day you walked on this stage the first time, and I know how special you are. I would love to continue working with you.”

He was in luck, because Simmons was feeling generous.

“John, you kinda broke my heart today, but I’m gonna give you one more shot, John,” Simmons said.

The “All of Me” singer then told the camera that he was relieved to keep the “poised and charismatic” artist on his team. Simmons had Legend “worried.”

As they worked with their advisors for the season — Little Big Town for Ballerini, Cynthia Erivo for Bublé, Coco Jones for Legend, and Kate Hudson for Levine — the contestants attempted to impress their famous mentors.

Team Levine’s Darius J, a 35-year-old from Pahokee, Fla., and Britton Moore, a 21-year-old from San Antonio, did just that with their haunting rendition of Radiohead’s “Creep.”

Ballerini called their performance “magic,” adding, “I think both of you have a great shot at winning this show. And you’re not on my team, and it makes me sad. Maybe we can change that.”

Levine selected Moore, and both Ballerini and Bublé wanted to steal Darius J. But no one had a chance. The “This Love” singer realized the value of Darius J, and he used his sole save. It was enough to keep Darius J on Team Levine.

Catch another Battles round Monday at 8 p.m. ET on NBC.