Transcript for Katy Perry Brings Cheerleader With Down Syndrome to the AMAs
E teenage dream coming true for one very special katy perry fan. You remember megan squire, the star of that amazing "roar" video. Katy was so inspired by megan's story, she personally invited her to be her date to one of music's biggest parties. Take a look at what happened. Their matto, here in the arizona desert, with an uplifting school spirit and a story that's touched the nation. Meet 18-year-old megan squire. For years, megan watched as her big sister cheered for her beloved high school. I went to all of the games. And she inspired me the most. She would sit at the gate and just lean her head over. Reporter: Megan decided to chase her dream. And with mykala helping her the entire step of the way, she tried out for her cheer team her freshman year. She worked really hard. You could tell it was something she wanted to do. Reporter: Megan made the team. And now, four years later, she's at the head of her cheer pack. Megan squire. Reporter: And even part of the homecoming court. Her friend, clayton, knew megan's incredible story needed to be told. So, to the soundtrack of katy perry's number one song -- ♪ I have the eye of the tiger dance in through the fire ♪ ♪ I am a champion ♪ Reporter: He directed this video for "gma's" contest. In less than a week, it went viral. Even touching katy's heart. So much so, that after she announced a different winning school, she did this -- I want to bring megan to a special event this fall as my date. What a fantastic honor for megan. And how sensitive of katy perry. Reporte AND ONE MONTH Later, katy delivered. Flying megan, clayton and the squire family to l.A. To be her special guests at the american music awards. Hi. Hi. Oh, my gosh. Finally, I get to meet you. You know that video was so important, not only to me. But I think thousands and thousands of people that watched it. Reporter: After posing for the squire family christmas card AND SIGNING A FEW CDs -- It says you inspire me because you do. You inspire me, too. Reporter: Katy offered some LAST-MINUTE AMAs INSIGHT. You probably get to walk the carpet. And just feel like a star. Even if you are. You're already a star. The whole country knows who you are. Reporter: Two days later, megan and clayton got red carpet ready. AND TOOK THE AMAs BY STORM. Rubbing shoulders with the rich and famous, with the hottest date in town. Tell me about katy. She is so nice. Megan is such an important, special date for me. One unlike any other date I've brought to any other award ceremony. Check out these seats. Reporter: Inside, the view wasn't so bad, either. Katy took the stage with a show-stopping performance. ♪ Reporter: Kicking off an unbelievable night and giving megan the experience of a lifetime. Yep. That's her, sitting right behind lady gaga. ♪ I got the eye of the tiger a fighter ♪ Reporter: An unforgettable story. And even bigger evening. And a teenage dream come true. Thank you, katy. We love you. How beautiful did she look? It was great. She was so close to gaga there. And you made a great point. You talk about how nice it is and warm and welcoming to kids. They made a great video for her. That's going to be a priceless christmas card, as
This transcript has been automatically generated and may not be 100% accurate.