Although Blake Shelton and Shakira collaborated on a country-pop song for the Colombian's newest record, they still remain enemies on 'The Voice.'

Shakira believes that she holds the upper hand over the 'Doin' What She Likes' country singer, and that upper hand is Miranda Lambert. The two work together to find a winner on the show, and Shakira calls Shelton's wife her little "spy."

"I had to have my secret weapon," the pop star says of Lambert. "She's like a spy in the Shelton headquarters."

Something tells us Shelton won't be giving up that easily -- especially to Shakira -- but the Colombian is determined to not let him win again.

"I am determined to defeat Mr. Blake Shelton," Shakira insists.

The pair's duet on 'Medicine' won't keep them civil while they're each trying to make one of their contestants victorious on the reality show, but Shakira does praise Shelton's voice on the song.

"He's got a great voice, he's got a manly voice, that's how a man should sing!" she tells Jimmy Fallon. Shakira's self-titled album dropped March 25, and it was the very first time country fans got to hear her duet with Shelton.