Wimbledon champion Serena Williams has revealed that sister Venus has been a huge influence on her success after defeating Agnieszka Radwanska today.

Williams believes that the fact she has always done everything with her sister is a big reason for her following Venus to Grand Slam victories in her career.

"I don't know what I would have if Venus didn't exist. I don't even know if I would own a Grand Slam title or if I would play tennis, because we do everything together," IOL Sports quotes Williams as saying.

"Growing up I copied Venus, everything she did. She was a real big influence for me. So when she started winning, I wanted it so bad. When she became number one I had to be number one.

"I had to work harder. I had to do everything in my power to get there. I have no idea what would happen if she wasn't around."