Serena Williams says she feared the worst after rolling her ankle against Petra Martic. After winning the first set, Williams was in full control of the match and seemed well set to move

into the last eight with minimum fuss. But at 2-2 and 30-15 on the Martic's serve in the second set, Williams approached the net and as she attempted to hit a backhand volley, her right

ankle gave way and she tumbled over. After a brief moment on the floor, Williams was able to continue and broke Martic with a forehand winner. At the change of ends, Williams received

treatment on her right ankle from the tournament trainer and had tape applied to an already heavily strapped foot. But to the credit of the six-time US Open champion, she stood firm and

because I've had a rough year with injuries. "I'm finally walking, but you guys were out here cheering so hard. "It really means a lot. It's a special place for me,

so thank you so much." September 1 marks two years since Williams gave birth to her daughter Alexis Olympia and the 37-year-old spoke warmly about being a parent. The American added:

"She was in my arms by now. It was amazing and the best day of my life. Now she is getting a little bit older she is starting to understand - she sees me on TV and says

'Mamma!' - sometimes she sees Venus and she says 'Mamma!'. "I honestly feel so fortunate to be out here playing as a mum, and I know there are so many mums - and

dads - out there working. "It's crazy because it's so hard to go to work, come home and be a full-time parent. When I go to bed now at 9pm, I am exhausted. Kudos to all the

parents out there. This is for you guys. "Pressure is a privilege and I am privileged to have that pressure."