Cape Town - Serena Williams considers the rivalry with her sister to be the 'ultimate' as she prepares to face Venus Williams in an exhibition match.
The most famous sisters in tennis will do battle for the 31st time at the Mubadala World Tennis Championship in Abu Dhabi next Thursday.
The younger of the dynamic duo leads there head-to-head 18-12, though Venus continues to surprise her more successful sibling.
One such occasion was in the round of 32 at Indian Wells earlier on the year, where she dispatched Serena in straight sets. Serena exacted revenge in the US Open later.
"This is going to be thrilling," the 37-year-old told The National.
"I love that Venus and I have had the ultimate rivalry. I have never played anyone I respect more and am wary of more than her. We, year after year and now I can say decade after decade, bring out the best in each other.
"It is never easy playing your best friend but she knows my game inside out, and has been so successful over me so many times. She is my role model and sister and best friend all rolled up into one. I could not be more fortunate to have her as my sister."
Serena Williams will then attempt to equal Margaret Court's longstanding Grand Slam singles title record when she travel to Melbourne for the Australian Open in January.
