Venus Williams has admitted that she was forced to stay positive during a difficult time of her life.
The world number 60 eased through to the second stage at the US Open after a 6-1 6-2 victory over Kirsten Flipkens on Monday.
Williams, who has been suffered from injury and illness over the past few years, admits that it has been a mental challenge for her to recover.
"I stay positive because I know I can play great tennis," The AP quotes Williams as saying.
"Sometimes you have to have losses. When I had losses, it always motivates me a lot to do better and to work harder."
Williams's last Grand Slam victory came at Wimbledon in 2008.