Coaches Christina Aguilera, Cee Lo Green, Adam Levine and Blake Shelton picked two members of their teams to face off by singing the same song. Then, along with one of their advisers, the coaches rehearse the song with the contestants.
"I never worry about the words," Aguilera said playfully to Frenchie Davis when she had a tough time with Beyoncé's "Single Ladies (Put A Ring On It)." "Just don't be afraid to attack it."
In exchanges at a piano, viewers really got to see how the stars worked as mentors – like hearing Levine demonstrate how to make "Leather and Lace" sound "smooth as butter."
The coaches also sat with their advisors, including Maroon 5 musical director Adam Blackstone and singers Reba McEntire, Sia and Monica, and have discussions with the singers about how they can improve.
Shelton's honesty really shined in this episode. "Be careful not to sing all over each other and just because you can do a lot of runs doesn't mean you have to do them constantly," he told soul singer Tyler Robinson.
The battle rounds themselves, contested in a disco-lit boxing ring, proved both formidable and fun as singers moved between performing a duet and upstaging each other. Seeing reactions of family and friends in separate holding pens as they awaited their loved one's fates added to the tension.
In the end, Davis beat out gospel singer Tarralyn Ramsey on Aguilera's team; cowboy Patrick Thomas defeated Robinson on Shelton's team; former athlete Casey Weston edged out Minnesota musician Mahoney on Levine's team; and petite dynamo Vicci Martinez beat out pop wunderkind Niki Dawson for Cee Lo Green.
Despite the competition, just hearing the quality of the contestants in battle was a thrill. As Green said after one match-up, "I enjoyed that so much."