Barrino grabbed runner-up Diana DeGarmo (search) in a bear hug and twisted her around as tears streamed down her face.
"Thank you so much," she sobbed. "I broke my shoe!"
Then she added: "I been through some things but I worked hard to get to where I'm at."
Barrino, a 19-year-old single mother from High Point, N.C., with a powerful, gospel-tinged voice, topped DeGarmo, an effervescent 16-year-old from Snellville, Ga.
DeGarmo continued smiling through tears in defeat: "I'm so proud to have come here with Fantasia. She's my girl and you guys will treat her well."
The judges of the Fox TV singing contest had pretty much crowned Barrino the winner the previous night, when she dazzled them with a powerful version of Gershwin's "Summertime" and two other songs.
But judges don't pick the winner — America does, through phone and text-message votes. Host Ryan Seacrest said a record 65 million phone votes were cast, up from 24 million for last season's finale.
Barrino receives a recording contract, following in the footsteps of the first two winners, Kelly Clarkson (search) and Ruben Studdard (search). Her first single will be a song she and DeGarmo both tried out Tuesday night: "I Believe," written by Tamyra Gray, a contestant from season one.
"Both of you have done an amazing job," judge Paula Abdul said before the results were announced. "You've made all three of us extremely proud."
"Think about it — you're the top two out of 70,000 people we saw," judge Randy Jackson added. "You should stand proud."
To fill the two-hour broadcast before the results were announced at the Kodak Theatre in Los Angeles, Clarkson and Studdard sang "The Impossible Dream" with Barrino and DeGarmo, and the two finalists did a feel-good version of the George Michael and Aretha Franklin duet, "I Knew You Were Waiting (For Me)."
Several other "Idol" finalists performed on an outdoor stage in the sunshine, including La Toya London, considered one of the strongest singers all along and a favorite to reach the final two. Jasmine Trias, who stayed in the contest longer than many thought she should thanks to a sunny personality and help from her home state of Hawaii, also performed.
All 12 finalists will go on tour together this summer, something they practiced for Wednesday with a lengthy medley of the series' previous songs.
Seacrest chatted with the judges in their dressing rooms beforehand, and several celebrities were interviewed on the red carpet, including Nicole Richie from the Fox reality show "The Simple Life" and Sharon Osbourne.
The "American Idol" finale may seem like the Super Bowl of karaoke, but this year it truly reached the level of momentous sporting event proportions. Thousands gathered at the Greensboro Coliseum in Greensboro, N.C., to cheer for Barrino and at the Georgia Dome in Atlanta to support DeGarmo.
Gray, from the competition's first season, sang "The Star-Spangled Banner," and the governors of both states had side bets: Georgia had to send peaches to North Carolina if Barrino won, and North Carolina had to send blueberries to Georgia if DeGarmo won.
Hometown pride aside, typically acerbic judge Simon Cowell summed up what the whole contest was about:
"Fame, stardom, a ton of money."