The double Australian champion expressed a gamut of feelings as she fought her way to a third round berth, admonishing herself for mishits, aghast over disputed line calls and daydreaming happily until she realised her grip on the match was slipping.

"I'm an emotional person," she said. "I mean, on and off the court I'm extremely emotional."

"I'm crying in the movies. I'm crying, you know, just (out of) sympathy. I was watching 'Prison Break' and I almost started crying -- I am a really emotional person.

"So it's no surprise to me that on the court I do tend to wear my emotions on my sleeve."

Williams said her sister was the opposite and used her emotional detachment to great effect.

"It can work against you and it can work for you," she said. "One thing I've always admired about Venus is you can never tell whether she's down or she's up -- she's just going steady and I've always loved that.

"I've been trying to make it work for me more than anything.

"(Venus) has always been that way, whether she's sad or she's happy she's kind of just like monotone sometimes.

"When she gets on the court, sometimes she gets really pumped and it's really exciting to watch. I just think it's amazing, those players that can just stay positive -- it messes with your mind."

Williams is attempting to come back after injury and a lengthy court case restricted her to just four tournaments in 2006, meaning she entered the Australian Open unseeded and ranked 81 in the world.

Despite questions about her physical conditioning, she said she hoped to contest 12 or 13 tournaments this year and remained hungry for more Grand Slam success.

"I want it all," she said.