2014 Australian Open - Li Na
IN PHOTO: Retired tennis star Li Na REUTERS

Chinese tennis great Li Na bid farewell to the sport that she played for more than a decade with a letter that she penned and shared on Facebook on Sept. 19. Li called her time on her 15-year professional tennis career due to her persistent knee injuries. Many tennis enthusiasts and colleagues were heartbroken over Li's decision to retire so let's relive the greatest moments that the 32-year-old has accomplished in her fruitful tennis career.

Li is the first and only Grand Slam champion from Asia

Li is the first and only Grand Slam champion in Asia. She won her first Grand Slam title at the 2011 French Open. She was seeded sixth at the tournament and easily cruised through the early rounds, beating Barbora Zahlavova-Strycova, Silvia Soler Espinosa, Sorana Cirstea, and Petra Kvitova. Li then defeated Victoria Azarenka, and Maria Sharapova in the quarterfinals and semifinals, respectively. In the finale, Li beat the defending champion Francesca Schiavone. More than 116 million Chinese reportedly watched her victory in the French Open.

Li won her second Grand Slam title at the 2014 Australian Open. Her victory made her the first Asian Australian Open champion. She entered the tournament as the No. 4 seed. She faced Ana Konjuh, Belinda Bencic, Lucie Safarova, and Ekaterina Makarova in the initial matches. In the quarterfinals and semifinals, Li triumphed over Flavia Pennetta and Eugenie Bouchard. She beat Dominika Cibulkova in the finals for to win her second Grand Slam title.

Li's career-best ranking is World No. 2

Li reached her career-best ranking of World No. 2 in February 2014. During this time, Li also became the highest-ranked tennis player from Asia.

Li released a book titled "My Life"

Li's book "My Life" was reportedly first published in Mandarin. It was later translated in English and released in December 2013. According to For The Win, Li's book is worth the read because it gives the readers a glimpse of how the Chinese athlete dealt with insecurity and self-doubt.

Li is included in Forbes' highest-paid tennis athletes in the world

Li has always been included in Forbes's list of highest-paid tennis athletes in the world. She ranked fifth in Forbes' 2014 list. During her last season, Li has earned $23.6 million, more than 50 percent of which came from her endorsements. When she won the 2014 Australian Open, Li received a huge bonus from Nike. Li is the only athlete who can wear patches on her Nike clothes.

Li retired from the sporting world of tennis as World No. 5. The last match that she played was her third round loss at the 2014 French Open.

Li said she would like to set up a tennis school and help China hone more athletes for tennis. "Like a pyramid, I believe only with a solid base, Chinese tennis can have a better future," Li said. Watch Li's emotional farewell to tennis at a press conference two days after she announced her retirement.

Video courtesy: YouTube/CCTV News