World number one Serena Williams denied there is a widening gulf between her and the other leading players after she claimed her tenth title of the year at the China Open Sunday.
The power-hitting American has had another season of domination, being confirmed as the top ranked year-end player last month, when she also become the first women to win more than $9 million dollars in a season.
The top seed eased to her second title in Beijing with a convincing 6-2, 6-2 demolition of Serbia's Jelena Jankovic.
But the 32-year-old said she was still being challenged by the other top-ranked women's players.
"Everyone is beatable I think at some point. I know I am," she said.
"Everyone is a threat, you know. I don't feel like I'm above anyone. I'm just playing and doing the best I can. That's all I can do.
"I'm just happy that I'm just working hard to be the best right now. Soon it will be someone else."
Williams is on a career total of 56 titles with 17 major wins.
She became only the fifth women to hold all four Grand Slam titles simultaneously at the 2003 Australian Open, and has finished the year at number one previously in 2002 and 2009.
Williams joins Justine Henin and Martina Hingis as a three-time year-end number one, with only Steffi Graf (8), Martina Navratilova (7), Chris Evert (5) and Lindsay Davenport (4) ahead of her.
When she arrived in Beijing last week, Williams told reporters she was not the greatest ever women's player, but that she was "maybe top five."
Williams won all of the 12 sets she competed in on her way to her victory in Beijing.
However, she claims her route to the title was not a simple one.
"I'm definitely being challenged. I was down a couple set points in a couple matches. I was able to pull through with that. Got a little lucky," she said.
"Everyone definitely presents a challenge. Every time I step out the a court it's a challenge. I'm vulnerable to not winning. I go out there focused the best I can every time."