Dellacqua into 3rd round at Open.

Casey Dellacqua believes she's never played better.

She's never been happier.

And on the evidence of her second-round 6-3 6-0 trouncing of Wimbledon semi-finalist Kirsten Flipkens at Melbourne Park on Wednesday, she is every chance of matching - or even bettering - her emotional run to the last 16 at the 2008 Australian Open.

That was pre-shoulder surgery, pre-ankle injuries and pre-motherhood.

"(The 2008 campaign at Melbourne Park) was all a blur for me," Dellacqua said on Wednesday after registering the most comprehensive victory of her grand slam career.

"I don't know how to explain it.

"I feel like I'm a bit more in control of my emotions now, understanding what's going on, where I'm at.

"You're such a different person when you're 22 to when you're 28."

Not just a different person, but a more accomplished tennis player, even though a ranking which is only now going to again dip back under 100 is yet to reflect it.

"In terms of my career and where I've come from, it's like my second career," said Dellacqua, who reached her best ranking of 39 way back in mid-2009."That's what I call it in a way.

"This is definitely the best career win for me in that sense, since my injuries and stuff."

Dellacqua was confident she had the 18th-seeded Flipkens on the rack on Wednesday when she went 2-0 up in the second set.

She knew the Belgian couldn't hurt her off the backhand and she returned well enough to break Flipkens' serve on six occasions in a match that was done and dusted in 63 minutes.

It was Dellacqua's first victory over a top-20 player since she beat Israeli Shahar Peer in Brussels three years ago, with the promise of more to come.

"I do believe I can continue to beat players like that," she said.

"If it's here at the Australian Open that would be great.

"But I'll definitely be having a good crack on Friday to continue this run here and hopefully keep it going."

Dellacqua will face China's Zheng Jie in the third round after she overcame American Madison Keys.