Kerber ready for challenge of being number one

Angelique Kerber is more than ready to face whatever challenges her new status as world number one and double Grand Slam champion bring. Kerber's US Open triumph over Karolina Pliskova on Saturday made her just the second woman, after China's Li Na, to win her first two Grand Slam titles after celebrating her 28th birthday. The German, who also won the Australian Open in January, will also be the oldest player to debut at world number one when her place atop the summit is made official on Monday