Romanian ready to seize Serena's mantle, says legend.
Swiss legend showing now signs of slowing down.
World number one looking ominously good.
Wimbledon champion closing in on elusive title.
Juan Martin del Potro saw off Hyeon Chung at the Cincinnati Masters.
Sloane Stephens and Angelique Kerber lose.
The ITF's proposal to turn the Davis Cup into a World Cup of Tennis has received the green light from tennis chiefs.
18-year-old aiming for the top but moving to the US.
The debate on five-set tennis continues.
"A 37-year-old should not be favourite."