The Oscar winner hit the stage with Vince Gill to belt out the theme tune to her new movie Country Strong, in which she plays singer Tim McGraw's alcoholic wife.
It marked Paltrow's first major live singing performance and earned her a standing ovation at the Bridgestone Arena in the country music of mecca Nashville, Tennessee.
And the performance has critics singing her praises.
Entertainment Weekly critic Ken Tucker claims that while Paltrow appeared anxious at first, she delivered a stellar performance.
He writes, "Strumming an acoustic guitar, looking a little nervous but singing the movie's title song in an expressive, surging tone, she didn't really need the assistance of the wonderful Vince Gill, there to give a polite country-industry imprimatur to Paltrow's efforts."
Meanwhile, New York Times music reviewer Jon Caramanica adds: "The surprise was that she didn't need (Gill)'s steadying hand nearly as much as some of the night's other performers."
New York Post writer Jarett Wieselman agreed, adding even though he was bracing for a "car crash" he soon changed his mind, calling her performance "solid - if not sensational".
But it's not just critics celebrating Paltrow's musical talents - country star Miranda Lambert told USA Today she thought the Oscar winner delivered a great show.
She adds to MTV News, "She sounded really country, I think. She seems very genuine."