Exposed! Glennis Grace Already Huge Star Before 'America's Got Talent' Performance

America’s Got Talent contestant Glennis Grace floored the judges last week when the 39-year-old single mom belted out a cover of Whitney Houston’s “I Wanna Run To You” that was deemed better than the late diva herself!

Social media exploded with thousands of AGT viewers who were eager to hear more of Grace, but RadarOnline.com has exclusively learned that she is not a new talent at all. In fact, she is a huge star!

“Glennis is already a big star overseas and has millions of fans on Youtube," a source told RadarOnline.com. "She is extremely well known and is also currently on tour right now in the United States with Ladies of Soul.”

One of Grace's recent Whitney Houston cover videos online even has over 18 million hits!

In October 2018, Grace is scheduled to perform a full Whitney Tribute concert at the AFAS Live in Amsterdam — a venue that seats up to 6,000 people.

As fans of the hit NBC show know, judges Simon Cowell, Heidi Klum, Mel B. and Howie Mandell are known for their tough criticism.

But after Grace stepped out on stage and delivered a mind-blowing rendition of Houston, the generally harsh panel of celeb judges had nothing but love for “the next Whitney!”

Instead of boasting about her career, which exploded in 2005, Grace played coy and said that she wanted to win “for her daughter.”