A look at some key dates in Serena Williams' illustrious Grand Slam tennis career:
September 1999: Serena wins the U.S. Open at age 17, becoming the first of the Williams sisters to claim a Grand Slam singles title.
September 2001: Venus and Serena square off in the U.S. Open championship, their first meeting in a Grand Slam final. Venus wins in a match that garners higher television ratings than Notre Dame-Nebraska, the college football game being aired simultaneously.
June 2002-January 2003: Williams pulls off the "Serena Slam," claiming four straight Grand Slam titles -- the French Open, Wimbledon and U.S. Open in 2002 and the Australian Open in 2003. Her opponent in all four finals is her older sister, Venus. In July 2002, Serena ascends to No. 1 in the world rankings for the first time in her career.
July 2003: Serena beats Venus in the Wimbledon final to claim her sixth career major title in what would be her final tournament of the year. Later that summer she had season-ending knee surgery, and her older half-sister, Yetunde Price, was murdered in September.
July 2004: Serena loses to 17-year-old Maria Sharapova in the Wimbledon final.
April 2006: Still struggling with a knee injury, Serena falls out of the Top 100 in the rankings.
January 2007: Serena enters the Australian Open looking out of shape and ranked No. 81 in the world. Getting visibly fitter round by round, she storms through the draw into the final, where she destroys Sharapova, 6-1, 6-2, in what BBC Sport terms "arguably the most powerful display ever seen in women's tennis."
July 2008: Venus defeats Serena in straight sets in the Wimbledon final for her fifth Wimbledon crown. Later in the summer, the sisters add to their Olympic medal collection by winning the gold medal in doubles at the Beijing Games.
September 2008: Serena defeats a then-No. 2-ranked Jelena Jankovic in straight sets in the final to win her third career U.S. Open title.
September 2009: In the notorious Saturday night semifinal against Kim Clijsters, Serena unleashes a profane and threatening verbal tirade against a lineswoman who calls her for a foot fault. Serena is docked a point, on match point, and loses the match. She is later fined $82,500 and placed on probation by the Grand Slam committee.
January 2010: Serena defeats Justine Henin in three sets in the Australian Open final to claim her 12th Grand Slam singles title, a mark that ties her with Billie Jean King.
July 3, 2010: Serena dominates Vera Zvonareva to win her fourth Wimbledon crown and 13th Grand Slam singles title. It would be the last Tour match she would play in nearly a year.
July 7, 2010: Serena slices a tendon in her foot by stepping on broken glass as she leaves a Munich restaurant. The injury requires surgeries in July and October 2010.
February 2011: Perhaps as a result of the surgeries and her immobilization, Serena develops a pulmonary embolism (blood clot) that requires her hospitalization in Los Angeles from Feb. 19-20. She is treated with anti-coagulant drugs.
Feb. 28, 2011: Serena requires emergency treatment for a hematoma in her stomach that likely developed as a result of her use of blood thinners.
June 2011: Serena returns to competitive tennis for the first time in more than 11 months, losing in her second-round match at Eastbourne, a warm-up tournament for Wimbledon.
June 21, 2011: Playing her first Grand Slam event in a year, Serena breaks down in tears of joy after winning her first-round Wimbledon match. The victory marked her successful return to tennis after a year of serious health issues.
June 27, 2011: Serena bows out in the fourth round of Wimbledon, falling in two tough sets to Marion Bartoli. Williams has not lost a match since.
July 2011-September 8, 2011: Serena wins 17 straight matches, including titles at Stanford and Toronto and a first-round win at Cincinnati. (She withdrew from the tournament after that match and appeared at Kim Kardashian's wedding later that weekend.) She has not dropped a set at the U.S. Open through the completion of the quarterfinals en route to the semifinals where, as the No. 28 seed, she will square off against No. 1 Caroline Wozniacki.
September 10, 2011: In defeating world No. 1 Caroline Wozniacki 6-2, 6-4 in the semifinals on Arthur Ashe Stadium on Saturday night, Serena records her 18th straight match victory. Williams, who has yet to drop a set at the 2011 U.S. Open, advances to her 17th career Grand Slam singles final.
September 11, 2011: Looking sluggish from the outset, Serena drops the first set of the final 6-2 to Samantha Stosur. In the first game of the second set, serving at 30-40, Serena celebrates an apparent winner with a loud "C'mon" before the point is over. Applying the intentional hindrance rule, chair umpire Eva Asderaki docks Serena the point, giving the break to Stosur. Serena complains bitterly to Asderaki immediately afterward and later during a changeover.
Temporarily energized, Serena breaks Stosur back in the second game of the second set, but is outplayed by Stosur, who goes on to win her first major title, 6-2, 6-3. After the match, Serena acknowledges that even without the hindrance call, she would have lost the match to Stosur. It is only Williams' fourth loss in 17 career Grand Slam singles finals.