As the inaugural winner of America's first modern singing competition, Kelly Clarkson once again had to enter uncharted waters for her second album.

Sure, her "American Idol" victory parade single, "A Moment Like This," had broken a 38-year-record held by the Beatles when it made the biggest leap to No. 1 on the Billboard Hot 100 in 2002. And sure, her 2002 debut album repeated that song's chart-topping success, spawning a Best Pop Vocal GRAMMY-nominated second hit ("Miss Independent") in the process. But by 2004, there was certainly no guarantee that the general public — who also had two other "Idol" winners (Ruben Studdard, Fantasia Barrino) and numerous other finalists with record deals to invest in — would be as interested without the springboard of the Fox juggernaut.

Let's not forget how the disastrous 10-time Razzie-nominated movie From Justin to Kelly alone could have sunk her career. And her numerous other "Idol" obligations — including the ratings flop "World Idol" in which she finished second behind Norwegian unknown Kurt Nilsen — didn't exactly help her cause, either.

Luckily, Clarkson had the courage of her convictions. She ditched "Idol" impresario Simon Fuller as her manager, regularly went head-to-head with RCA boss Clive Davis, and largely abandoned the lightweight R&B/pop of her debut for an assertive blend of angst-ridden guitars, introspective lyrics and skyscraping choruses designed to be belted out at maximum velocity. The result? Her biggest album to date: Breakaway.

From the moment she won "Idol," Clarkson accepted that she'll never fully escape her prime-time roots ("I'm the first one, so it's going to be on my grave" she told MTV in 2005). But with Breakaway, she didn't just prove to the world that she was a full-fledged artist — she ensured that it would be followed by countless other milestones and achievements, too.

In honor of the album's 20th anniversary, take a look at some of the ways Breakaway helped Clarkson come into her own.

It's One Of The '00s Biggest Selling Albums

Breakaway entered the Billboard 200 at No. 3 with first-week sales of 250,000, a figure 47,000 short of that achieved by her chart-topping debut, 2003's Thankful. But proving that the race to multi-platinum status is often a marathon, not a sprint, Clarkson's second studio effort sold consistently throughout the following 12 months; in fact, it stayed inside the Top 20 for more than a year. And by the end of 2005, it had more than doubled its predecessor's sales.

Indeed, only Mariah Carey's comeback The Emancipation of Mimi and 50 Cent's sophomore The Massacre sold more copies domestically that year. And thanks to the enduring appeal of hits such as "Since U Been Gone" and the title track, Breakaway continued to sell throughout the rest of the decade and beyond. To date, its worldwide sales tally of 12 million makes Breakaway one of the most successful by a female artist in the 21st century.

It Proved She Could Rock

During her time on "Idol," Clarkson largely stuck to songs by female artists that showed off her range — but what it didn't show was her love for rock music. After flirting with the genre on Thankful with tracks like "You Thought Wrong," Clarkson went all out on its riff-heavy follow-up.

With a pop-rock vision in mind, she recruited Ben Moody and David Hodges of Evanescence for two tracks ("Because Of You," "Addicted") and Our Lady Peace frontman Raine Maida on "Where Is Your Heart." She channeled Alanis Morissette on "I Hate Myself For Losing You" and any number of emo favorites on "Hear Me." And kiss-offs "Behind These Hazel Eyes," "Walk Away" and "Gone" — the former two co-written by Clarkson — introduced the guitar-driven, belt-out melodies that soon became her signature. (Even then-reigning pop-rock queen Avril Lavigne saw Clarkson's potential, offering "Breakaway" for the album's track list after it didn't make the cut for her 2002 debut, Let Go.)

Of course, it was the charged-up lead single, "Since U Been Gone" that had the most impact. Reaching No. 2 on the Hot 100 and topping Billboard's Pop Airplay chart for 7 weeks, Breakaway's second single solidified her as a mainstream star in her own right — and one that could rock.

The song is such a jam, in fact, that it's even spawned several rock-star salutes. Tokyo Police Club, A Day to Remember and Clarkson'sall-time favorite band Toadies are just a few of the rockers who've put their own spin on the crossover hit. While the "Idol" winner had previously been treated with suspicion by the cool crowd, Breakaway saw her embraced as one of their own.

Following in the platform-boot footsteps of Spice Girls, Clarkson parted company with manager (and "American Idol" creator) Simon Fuller ahead of Breakaway's recording, another sign that she didn't want or need to rely on her rather manufactured past.

She continued to assert more creative control in the studio, too. It was her decision to team up with Evanescence's Moody and Hodges, and — ignoring her RCA label's impresario Clive Davis' advice, which essentially amounted to "stick to singing" — the star co-wrote six of the album's 12 tracks.

This included two highly personal efforts: "Behind These Hazel Eyes" is a breakup anthem about a "dipstick who completely screwed up," while "Because Of You" is a tearjerking ballad inspired by her relationship with her estranged father. According to Clarkson, Davis had slated the latter on first listen, but she refused to back down — and had the last laugh when the track became one of her defining hits.

It Spawned Four Consecutive Top 10 Hits

Despite the launchpad of America's biggest TV show, Clarkson's debut album could only spawn one post-"Idol" Top 10 single; even the tie-in with divisive rom-com Love Actually failed to help "The Trouble with Love Is" chart. But the vocalist had no trouble racking up the hits with its follow-up.

"Since U Been Gone" was only kept off the top of the Hot 100 by 50 Cent's "Candy Shop," while the title track — released as a stopgap single as the theme to The Princess Diaries 2: Royal Engagement — "Behind These Hazel Eyes," and "Because Of You" all achieved a Top 10 position, too. In fact, Clarkson very nearly made it five out of five, but "Walk Away" peaked at a frustratingly close No. 12.

As if that wasn't impressive enough, "Breakaway" also spent a remarkable 21 weeks atop Billboard's Adult Contemporary chart, surpassingCeline Dion's "Because You Loved Me" andPhil Collins' Tarzan hit "You'll Be In My Heart" as its longest-running No. 1 to hail from a film.

It Made Her A GRAMMY Winner

Clarkson has been recognized at the music industry's biggest night of the year on no fewer than 17 occasions (as of press time), with her first nomination coming for her first post-Idol single, "Miss Independent," in 2004. The star didn't win Best Female Pop Vocal Performance first time around, but she did emerge victorious in the same Category two years later thanks to the instant classic "Since U Been Gone." This made her the first "American Idol" graduate to win a coveted GRAMMY, paving the way for Carrie Underwood, Fantasia and Jennifer Hudson.

Furthermore, Clarkson also triumphed over the likes of Gwen Stefani, Sheryl Crow and the one and only Paul McCartney when Breakaway was declared Best Pop Vocal Album in 2006. It was a double whammy that both fully validated the singer as a credible artiste and put further distance between her flourishing career and her talent show beginnings. To cap her remarkable evening off, the star also brought the house down with a spellbinding performance of "Because of You."

Read More: How Many "American Idol" Winners Have Won GRAMMYs? A Rundown Of Wins And Nominations For Kelly Clarkson, Carrie Underwood & More

Even with a No. 1 single and album under her belt, Clarkson still had to share the bill on her first tour with a fellow "Idol" contestant — and not even a winner. 2004's Independent Tour saw her co-headline with second season runner-up Clay Aiken. But thanks to the mammoth success of Breakaway, she was able to hit the road completely on her own.

Clarkson appeared to be so thrilled with this development that she embarked on three different treks to promote the record. Firstly, she played 66 dates across North America, Australia and Europe for The Breakaway Tour. Then, she focused on the U.S. and Canada for a series of shows named after its second single, "Behind These Hazel Eyes." And finally, she wrapped up the album's campaign in the summer of 2006 with the domestic Addicted Tour. By this point, she'd undeniably proved she didn't need the safety net of the Idol umbrella to attract a crowd.

While the first season of "American Idol" gripped the country (over 110 million votes were cast throughout), it failed to make anywhere near the same impact internationally. With the format being adapted for 56 regions, most talent show audiences were inevitably more invested in their own homegrown talent. And this being the pre-streaming, pre-broadband age, it wasn't always easy for most to watch it in the first place, too.

Clarkson was therefore a virtual unknown when she launched debut album Thankful worldwide. And although "Miss Independent" became a hit in the UK and Australia, there was little to suggest she'd continue to connect outside her homeland.

Breakaway, however, proved to be a massive success in territories unfamiliar with Ryan Seacrest and co. It shifted 1.5 million copies on the other side of the Atlantic and went seven-times platinum down under, all of which helped it become the world's seventh biggest seller of 2005. And Clarkson has deservedly remained a global superstar ever since.