'The Voice' 's Battle Rounds Conclude

Goodbye, battle rounds!

The Voice‘s coaches finalized their teams for the knockout rounds on Tuesday, paring down their roster from 12 singers to just six, plus the two new teammates they each added with their strategic steals.

Usher was the only coach who had an available steal and he used it to nab a Latina pop singer from Team Shakira in the final moments of the show. Shakira pitted Bronx native Cathia, an aspiring Latina pop star, against Cuban-born Mary Miranda – and in a bold move assigned the singers to perform her own song, “Antes Des Las Seis.”

Usher teasingly wondered whether the choice was “narcissistic,” but fiery (and slimmed-down) new mom Shakira explained, “I wanted to see if they would try to imitate my voice or make it their own.”

Make it their own they did, and the two earned praise from all four judges for the song they performed in Spanish.

Although Shakira told the young women, “I like you both equally,” she ultimately chose Mary, singling her out for her signature vibrato and her voice that “is just so sweet … like cotton candy.”

But after Adam Levine threw an encouraging look to Usher, the new coach slapped his buzzer to save Cathia, who burst into tears of joy.

“You really sold me at the end of your performance,” Usher said.

Tuesday also provided another glimpse of a singer all the judges think has great potential to win the show: Team Adam’s Sarah Simmons, a 22-year-old music student from Memphis.

Levine paired Simmons with Hawaiian folk singer Duncan Kamakana, and the pair performed Lady Antebellum’s “Wanted You More” – and received additional coaching from Lady A’s own Hillary Scott.

Blake Shelton in particular seemed awed by Simmons talent. “Sarah, you’re one of my favorite singers I have ever heard in my life,” he said.

“As a fan of this show I’m going to buy all of Sarah’s music as soon as it’s available,” he added later. “As a coach on this show she’s definitely a problem for me.”

RELATED: Shakira: Losing Baby Weight for The Voice Was ‘Stressful’

The evening also pitted the oldest competitor in the show, Shawna P, 45, of Alabama, against one of the youngest: 19-year-old Brandon Roush, who works with autistic kids in Louisville. The duo sang “Piece of My Heart” by Janis Joplin, and coach Shakira dubbed the battle one of eagerness versus experience.

This time, experience won out. “She is in a way so perfect as a singer,” Shakira said of picking Shawna.

In other battles: Adam chose college student Amy Whitcomb over Latin pop singer Agina Alvarez; Blake chose Justin Rivers over the Morgan Twins; and Usher picked introverted indie rocker Michelle Chamuel over pop singer Chelsea M.

The knockout rounds begin Monday.