Alona Volodymyrivna Bondarenko Dyachok (Ukrainian: Альона Володимирівна Бондаренко, born 13 August 1984 in Kryvyi Rih, Ukrainian SSR) is a Ukrainian tennis player. She has a younger sister Kateryna Bondarenko who also plays on the Tour. She formerly paired with her older sister Valeria in doubles. She is currently ranked World No. 114 in singles and World No. 327 in doubles by the WTA.

Her career high singles ranking was Number 19, achieved on 14 April 2008. She defeated former World No. 1 Jelena Janković in the third round of the 2010 Australian Open. She won the 2008 Australian Open women's doubles tournament with her sister Kateryna, beating Victoria Azarenka and Shahar Pe'er in the finals.

Bondarenko started competing in the pro tour in 1999 at the age of 14, were she competed in ITF Circuit, she reached two second rounds in Tallinn, Estonia and Kharkiv, Ukraine, two first-round exits in Bucharest3 in Romania and in Kedzierzyn-Kozle, Poland, and failed to qualify in two events as well in Tbilisi and Batumi both were held in Georgia.

Caroline Wozniacki (born 11 July 1990) is a Danish professional tennis player. She is a former world no. 1 on the WTA Tour. As of 23 January 2012, she held this position for 67 weeks. She is the first Scandinavian woman to hold the top ranking position and 20th overall.

Since her WTA debut in 2005, she has improved her year-end ranking each year until finishing on top in both 2010 and 2011. She has won 18 WTA singles titles as of August 2011, three in 2008, three in 2009, six in 2010 (the most since Justine Henin's ten in 2007), and six in 2011. She was runner-up at the 2009 US Open and the 2010 WTA Tour Championships in Doha to Kim Clijsters. She won the 2006 Wimbledon Girls' Singles title but has yet to win a women's Grand Slam title. She also holds two WTA titles in doubles.

Wozniacki is the daughter of Polish Roman Catholicimmigrants, Piotr and Anna Wozniacki. Anna played on the Polish women's national volleyball team, and Piotr played professional football. The couple moved to Denmark when Piotr signed for the Danish football club Boldklubben 1909. Wozniacki's older brother Patrik Wozniacki is a professional footballer for Hvidovre IF in Denmark.

Serena Jameka Williams (born September 26, 1981) is an American professional tennis player and a former world no. 1. The Women's Tennis Association has ranked her world no. 1 in singles on five separate occasions. She became the world no. 1 for the first time on July 8, 2002 and regained this ranking for the fifth time on November 2, 2009. She is the only female player to have won over $35 million in prize money.

Her 27 Grand Slam titles places her ninth on the all-time list: 13 in singles, 12 in women's doubles, and 2 in mixed doubles. She is the most recent player, male or female, to have held all four Grand Slam singles titles simultaneously and only the fifth woman in history to do so. She was also the first woman, along with sister Venus Williams, to hold all four Grand Slam doubles titles simultaneously since Martina Hingis did so in 1998. Her 13 Grand Slam singles titles is sixth on the all-time list. Williams ranks fourth in Grand Slam women's singles titles won during the open era, behind Steffi Graf (22 titles) and Chris Evert and Martina Navratilova (18 titles each). She has won more Major titles in singles, doubles, and mixed doubles than any other active player, male or female.