That night, "Jar of Hearts" "went to the top of the iTunes chart, and just chilled there," recalled the outgoing, tatted-up 27-year-old Perri. "July 1, I covered all my shifts and flew out to New York City. . . . I never waitressed again."
Instead, the Archbishop Ryan grad, who'd been too shy to perform in coffee shops, was suddenly meeting with major labels, giving interviews on live TV, earning comparisons to Fiona Apple and Alanis Morissette, and entertaining thousands of Facebook friend requests.
She was also watching in disbelief as the song she'd written in her childhood bedroom got downloaded nearly 47,500 times in a week.
Then, just as fast, she was making a record.
"We had to rush the creative process to capitalize on the success of 'Jar,' " said Pete Ganbarg, the guy who signed her to Atlantic Records.
Perri's mission: Prove she was no one-hit wonder, in one month. Luckily, she had the material to pull it off.
She'd been writing songs since age 15. Big brother Nick Perri, a star musician at Father Judge High School who went on to play guitar for Shinedown and Perry Farrell, inspired her teenage foray into music.
Retired Father Judge and Nazareth Academy High School theater director Carol Greco remembers both Perri kids. "Nick was a very accomplished guitarist. He was in my plays and was very, very talented, and good looking, too," Greco said. "[Christina's] brother was the shining star. She was a little in awe of him."
Before Christina graduated from Ryan, she attended Nazareth for two years. Greco tapped her for female leads in Father Judge productions of "Fiddler on the Roof" and "The Outsiders." "Christina always stood out - she was always an individualist," Greco said. "She was just like her brother, always so well prepared."
She was also always a romantic.
For her first album, "lovestrong.," Perri raided her reserve of songs about relationships gone wrong. She described the 12-track result as "a breakup album pretty much about one guy," a dude she dated five years before marrying another man for 18 months.
"Jar of Hearts" was the EP's main attraction. Melancholic "Arms" went gold. Bittersweet "Distance" featured label-mate Jason Mraz. The LP sold about half a million copies in the U.S.
Perri still happily performs "lovestrong." hits for fans. But she's no longer so lovelorn.
All about her
"When my first album came out, I felt as though it was way behind me," she said.
Post-"lovestrong.," she wrote her next - and best-selling (nearly 4 million downloads) - hit, "A Thousand Years," for "Twilight: Breaking Dawn." (She's a self-confessed "Twihard.") The song's now a standard at weddings.
But she made her second album all about her. With "Head or Heart," she said, "I feel so incredibly parallel with it, in the same boat."
"It's about my relationship with myself, learning to be myself on the planet, to be myself and trust myself," she said of the album, which dropped this spring.
"Human," the album's first hit single, speaks to the demands of success, although life for the onetime waitress is definitely more comfortable than it used to be - Perri's bought herself a house in L.A. and lets a fluff-and-fold do her laundry.
"I Believe" is dedicated to her favorite nonprofit, To Write Love on Her Arms, which supports people struggling with addiction and self-harm.
"Burning Gold" recounts her decision to move from Philly to L.A. The song quotes Mom and Dad, Mary and Dante Perri, hairdressers married 36 years, who, according to the lyrics, told her, "Honey, you won't get there if you don't believe."
Perri said that the track was "an ode to my family" and "the first time [my music] ever mentioned my parents." Across her clavicle, the most prominent of her 70-some tattoos spells out "La Mia Famiglia." She got it when she was 19. She called herself "a family gal."
Although she's been recording and touring - solo, with James Blunt, and, next month, with One Republic, then September and October with Demi Lovato - almost nonstop since her big break, "I literally come home every single time I can," she said. Perri often jokes that "181 Perris," including members of her mom's Polish and dad's Italian sides, show up for her local shows.
But she doubts that she'll visit with Mom-mom, hang out in Philly or even walk the O.C. boards this weekend. There's just no time to chill with her lager-drinking buds at the Eddington House, where she waitressed six years; grab one of Steve's Steaks, on Cottman; or visit the campers at Bensalem Rec, where she performed summer theater and made sets.
Instead, she's got band rehearsals and appearances on "The Today Show" and "So You Think You Can Dance."
Her schedule is packed. Still, she's penciled in plans to go home for her mom's 60th birthday this fall, plus Thanksgiving and Christmas. She also wants to spend as much time as possible in Cali with her new niece - Nick and wife Misi's one-month-old, Tesla Mia. Perri called the babe "the most beautiful thing."
Life remains a whirlwind. But, somehow, it feels stable.
Perri said that the single "Trust" is "my theme song."
"Four years ago, I was asking you if you wanted sparkling or still water. Now, everything is a pleasant surprise. When people ask me what's next, I say I want to grow cucumbers in my backyard. I want to sing. I want to visit every country. I want to make my family proud. Everything happened so quickly for me. I wasn't very present. Now, I'm taking it one day at a time. I'm enjoying it for the first time."
Christina Perri "Head or Heart Tour," Revel Ovation Hall, 500 Boardwalk, Atlantic City, 9 p.m. Friday, $29.50, $34.50 and $49.50, 800-745-3000, Ticketmaster.com.
On Twitter: @LaMcCutch