In a new interview with NPR, Serena talks about her book, On the Line, which documents her life in tennis, including her on-court relationship with Venus. Serena is close to her older sister, but she says she always felt like the underdog:

Venus was the big star. When we were growing up, it was a lot about Venus—it needed to be about Venus, because she was an incredible player. And that actually, being the little sister, the one that wasn't as strong, wasn't as good yet, gave me encouragement and the fight I have in my game.

While most of us can remember competing against our siblings at some point, being constantly pitted against your sister seems like it could lead to a truly fraught relationship. Not so for the Williams. Serena says she once told Venus that "we'll be sisters later." On the court, they are rivals, but after the game is over they go right back to normal. Serena explains:

In the book I talk about how difficult it was to be there. First of all, I didn't believe I could, and second of all, I was playing my sister. I had to come up with something new, that, right now, we're competitors, but the moment we shake hands and we're done with this match, we're sisters. I'm always happy for Venus, and she's always happy for me.

Serena also talks about an incident early in her career, when she was playing in a tournament at Indian Wells, and her sister was forced to drop out because of an injury. Serena says the angry fans booed and shouted racial epithets. "I was crying in my towel at the changeover. I would cry, and I knew that I had to go on," she recalls. "But I got strength from a lot of the situations like Althea Gibson, who ended up having to sleep in her car because of the color of her skin...And I thought 'wow, this is nothing compared to what they went through,' and I was able to draw strength from that to finish the match."

Serena does mention the recent incident at the U.S. Open, where she threatened a lineman. She offers a weak—but probably honest—explanation for her actions, but she continues to assert that the lineman's call was at fault. When asked "Why do you think that happened?," Serena responds: "A lot of things factored into it... This is a case where I may, not may, I definitely wore my emotions a little too far on my sleeve—on a bad call." She adds, "Just so you know, this is not the first time this happened in tennis, and I definitely think one moment doesn't make your career or define you as a person."

Serena Williams Puts Her Life Story Into 'On The Line' [NPR]

[New York, September 14. Image via INF]

[Queens, September 14. Image via Getty]

NEW YORK - SEPTEMBER 14: Serena Williams (R) and Venus Williams celebrate championship point after defeating Cara Black of Zimbabwe and Liezel Huber in the Women's Doubles final on day fifteen of the 2009 U.S. Open at the USTA Billie Jean King National Tennis Center on September 14, 2009 in the Flushing neighborhood of the Queens borough of New York City. Williams/Williams defeated Black/Huber 6-2, 6-2. (Photo by Matthew Stockman/Getty Images)

Hey guys!!!

I want to amend my press statement of yesterday, and want to make it clear as possible - I want to sincerely apologize FIRST to the lines woman, the USTA, and mostly tennis fans everywhere for my inappropriate outburst. I'm a woman of great pride, faith and integrity, and I admit when I'm wrong.

I need to make it clear to all young people that I handled myself inappropriately and it's not the way to act — win or lose, good call or bad call in any sport, in any manner.

I like to lead by example. We all learn from experiences both good and bad, I will learn and grow from this, and be a better person as a result.

As mentioned earlier, Williams is being fined $10,000 and an investigation is under way to determine whether there should be additional punishment.

Serenajwilliams [Twitter]
Press Statement Amendment [SerenaWilliams.com]

Earlier: Serena Williams Fined $10,000 For U.S. Open Incident
So What Happens Now?

[Queens, September 13. Image via INF]

[Queens, September 13. Image via Getty]

Kim Clijsters from Belgium and her daughter Jada with her trophy after defeating Caroline Wozniacki from Denmark to win the Women's Final US Open match at the USTA Billie Jean King National Tennis Center September 13, 2009 in New York. AFP PHOTO / TIMOTHY A. CLARY (Photo credit should read TIMOTHY A. CLARY/AFP/Getty Images)

[Queens, September 9. Image via Getty]

Danish player Caroline Wozniacki celebrates after winning against US tennis player Melanie Oudin during their quarterfinals match of the 2009 US Open at the USTA Billie Jean King National Tennis Center in New York, September 9, 2009. Wozniacki qualified for the semifinals winning 6-2, 6-2. AFP PHOTO/Emmanuel Dunand (Photo credit should read EMMANUEL DUNAND/AFP/Getty Images)

NEW YORK - SEPTEMBER 09: Caroline Wozniacki of Denmark celebrates match point against Melanie Oudin of the United States during day ten of the 2009 U.S. Open at the USTA Billie Jean King National Tennis Center on September 9, 2009 in the Flushing neighborhood of the Queens borough of New York City. (Photo by Jim McIsaac/Getty Images)

[Queens, September 8. Image via Getty]

Kim Clijsters of Belgium reacts during a US Open quarterfinal match against China's Na Li at the USTA Billie Jean King National Tennis Center on September 8, 2009 in New York. AFP PHOTO/TIMOTHY A. CLARY (Photo credit should read TIMOTHY A. CLARY/AFP/Getty Images)

A year ago, Oudin was ranked 221st and lost in the first round at the U.S. Open. Until this June, when she bested former No. 1 Jelena Jankovic at Wimbledon, Oudin had never won a Grand Slam match. But this past Monday, Oudin beat 13th-seeded Nadia Petrova, after knocking out Maria Sharapova (29) and Elena Dementieva (4), thus winning herself a slot in the quarterfinals.

Oudin has been hailed as the "Cinderella story" of the tennis, America's sweetheart, and the "darling" of the U.S. Open. As Danielle Friedman notes for the Daily Beast, Oudin is receiving so much attention partially because of her perky blonde ponytail and pink sneakers stamped with the word "Believe:"

For American women's tennis, Oudin's arrival has been a long time coming. Not since the 1970s, when Chris Evert rose to the top of the pro-tennis scene, has this country seen such a girl-next-door-style sweetheart in the sport, said Michelle Beadle. "From Day 1, I've never heard the Williams sisters referred to as sweethearts," she added. While Jennifer Capriati briefly filled that role in the 1990s, she fell from grace after being arrested for shoplifting and marijuana possession.

Beadle, a sportscaster for ESPN, says Oudin's charm stems, at least in part, from her good looks. "She looks like she just scrubbed her face with Noxzema. She's like Reese Witherspoon playing this role in a movie. She looks like a girl whose summer job is to sell clothes at Abercrombie."

But even more important than Oudin's charm is her backstory, which has led many to call her the American "comeback kid." After training for years, Oudin rose from relative obscurity to national fame in a few short days. She first picked up a racket at age seven. She began hitting tennis balls out of a bucket with her grandmother and twin sister, Katherine. At age nine, Melanie and Katherine began working with coach Brian de Villiers, but when she was 12, Melanie decided that she wanted to be home-schooled, so she could focus all her energy on tennis, while Katherine chose to continue in school. As kids, the sisters played each other on a makeshift court, piling up jackets to serve as a net, but neither one of them ever thought they'd end up competing against players like Petrova or Jankovic. "It's not like we were saying, 'Oh, we're going to be there one day,'" Katherine said, in an interview with ESPN. "But Melanie's just always believed in herself. It's amazing."

Although her sister is her biggest cheerleader, Oudin won another fan yesterday: Roger Federer, who said, "She's beaten great players on the way. It's nice for a change that somebody's coming up we haven't heard about before. Many women now are kind of known."

When Oudin defeated Sharapova on Saturday, she sat down on the court and cried in disbelief. But she shed no tears after her win on Monday. "It's kind of hard to explain how I've done it," Oudin told the USA Today. "Today, there were no tears because I believed I can do it. Now I know I do belong here. This is what I want to do. I can compete with these girls no matter who I'm playing. I have a chance against anyone."

While her twin sister celebrated by throwing her racket into the air, Katherine Oudin sobbed with joy and pride. "Right now, I think she'll play Serena in the finals," she said. "We're not going anywhere."

Oudin is set to play against 19-year-old Caroline Wozniacki from Denmark on Wednesday. Wozniacki, ranked No. 9, currently has more wins on tour than anyone this year, but in a stadium that goes wild and blasts "Just 17" after each Oudin win, Wozniacki's suddenly seem not to matter, and she knows it. "Hopefully," Wozniacki said, "someone from the crowd will cheer for me."

Cinderella Story Continues: Oudin Wins Again At U.S. Open [USAToday]
Melanie Oudin Is An Upset Winner Again At U.S. Open [LA Times]
Tennis' New All-American Sweetheart [Daily Beast]
Melanie Oudin The Star In A US Open Full Of Upsets [Sentinel]
US Open: Melanie Oudin Comes From Behind Again [ESPN]

[Queens, September 3. Image via Getty]

Jelena Jankovic of Serbia returns a shot against Yaroslava Shvedova of Kazakhstan during their 2nd round US Open match at the USTA Billie Jean King National Tennis Center September 3, 2009 in New York. TOPSHOTS / AFP PHOTO / TIMOTHY A. CLARY (Photo credit should read TIMOTHY A. CLARY/AFP/Getty Images)

[Queens, New York; September 2. Image via Getty]

US number two seed tennis player Serena Williams during her match with Hungary's Melinda Czink during their second round match during day three of the 2009 US Open at the USTA Billie Jean King National Tennis Center, in New York, September 2, 2009. AFP PHOTO/Emmanuel Dunand (Photo credit should read EMMANUEL DUNAND/AFP/Getty Images)

[U.S. Open, Queens, New York, September 3. Image via INF]

The Good:
Anna Wintour looks typically impeccable...but what's really awesome is that this appears to be the same dress she wore to the Sex and the City premiere!
I have a strange, platonic couple-love for NYC mayor Mike Bloomberg and his much taller, "Best Dressed List" lady friend Diana Taylor.


The Bad:
Keisha Whitaker (yes, Forest's wife) is certainly stunning, but her frock puts me in mind of Bat Mitzvah circa 1994.
I like that Maria Sharapova's working not obviously sexy, but it's one layer too many...and the purse makes me think that she may not really know what she's doing.
I'm really wishing we could see legendary tennis player Boris Becker's lower half here, because if it's half as rad as the suit/hair, we're in business.


The Martha:
Martha Stewart does unabashed "mom."

[Images via Getty]