China's Li Na said her ground-breaking career can be traced back to the death of her father when she was 14, a pivotal moment which meant tennis success was her "only chance."

Li, in candid comments following her shock retirement last week, said she had to grow up quickly when left to support her mother, a realization which shaped her life.

"I think I was a pretty normal girl in the way I grew up (but) what totally changed my life was when my father passed away," she said in Wuhan.