Serena Williams has admitted that she was pushed "really hard" by Jie Zheng at Wimbledon this afternoon.
Williams was taken the distance by her Chinese opponent before she eventually served out to take the deciding set 9-7.
Reflecting on the match, former world number one Williams insisted that she is playing the "best" that she can.
"She always pushes me really hard," he told BBC Sport. "I thought, third set, if I'm going to go out I'm going to go out with a bang.
"I'm just fighting everything. She's playing unbelievable on grass. I'm just playing the best I can."
Williams has been crowned champion four times at SW19.