VIDEO: American Idol's Phillip Phillips Performs National Anthem At World Series

American Idol season 11 winner Phillip Phillips took his winning voice to the baseball diamond in game one of the World Series on Wednesday night to kick off the showdown between the San Francisco Giants and the Detroit Tigers with his rendition of the National Anthem.

Phillips was cool as a cucumber as he smoothly made his way through the difficult song, hitting all the notes with his trademark calm.

While he might have looked put-together on the outside, however, Phillips later tweeted about the stressful scenario. "Gaaaaaaahhhhh leeeeeeeee that was nerve racking!!" he wrote, and later Instagramed a picture of himself in which he betrayed his team loyalties. "Awesome," he wrote. "Let's go Giants, Gotta represent Buster Posey!"

In upcoming Series games, The X Factor's Demi Lovato, New Girl's Zooey Deschanel and Glee's Matthew Morrison are scheduled to perform the National Anthem.

Watch the performance here:

Get the FREE Uinterview iPad app here and watch our videos anywhere.

For more like this:

Phillip Phillips Wins 'American Idol' Over Jessica Sanchez

RECAP: Jessica Sanchez & Phillip Phillips Duel On 'American Idol'

'American Idol' Top 2 Picks Jessica Sanchez, Phillip Phillips

Jessica Sanchez, Joshua Ledet, Phillip Phillips Keep On Wowing 'American Idol'

Joshua Ledet, Jessica Sanchez Get Standing Ovations On 'American Idol'

RECAP: Jessica Sanchez Dominates 'American Idol' With Whitney Tribute

RECAP: 'American Idol' Top 5 Duke It Out