Piers Morgan has revealed that Susan Boyle was extremely nervous before performing her pre-recorded live version of the Rolling Stones’ “Wild Horses” on the “America’s Got Talent” final in September.

The “America’s Got Talent” judge, who witnessed Boyle’s rise to fame first hand while judging for “Britain’s Got Talent,” told Britain’s Daily Mail that fellow “AGT” judge Sharon Osbourne had to calm the Scottish singing star down before she took the stage.

"Susan, despite what some people seem to think, is a very funny, quick-witted lady. But like a lot of performers, she gets incredibly nervous before big performances,” Morgan said.

Boyle reportedly told Morgan before her highly anticipated U.S. performance: “It’s a bit daunting, thinking of so many people watching me sing here for the first time.”

But the TV judge eased the singing sensation’s mind, telling her: “Barbra Streisand apparently throws up before every show.”

Unfortunately, Morgan’s reassurance wasn’t enough, and Sharon Osbourne had to come to Boyle’s rescue.

"Later her nerves worsened, so Sharon Osbourne went up and calmed her down brilliantly,” Morgan said.

"[Sharon told me], 'I just looked her in the eye and said - Susan, you're a winner, not a loser, and you're a fighter like me, so get out there and show them all what you can do!'"

In the end, Morgan, one of SuBo’s biggest fans, chalks it up to a bit of normal stage fright, and wasn’t a bit surprised when Susan got it together and banged out an incredible performance.

“None of us needed to worry about Susan Boyle,” Morgan said. “From the moment the studio lights dimmed and she walked out to the microphone, the place erupted.

"And her rendition of the Rolling Stones' 'Wild Horses' was so technically perfect, and so hauntingly beautiful, that it gave me the chills."