Casey Dellacqua is the last remaining Aussie in the singles draw at the US Open after powering her way to the Round of 16. Dellacqua overcame young Czech star Karolina Pliskova 6-3 3-6 6-4 on the weekend, with her world ranking continuing to soar.

The 29-year-old sat outside the top 200 this time last year, having been dumped out of Flushing Meadows in the first round. However the West Australian is now set to move inside the world’s top 25, becoming the highest ranked Aussie in the process.

“I am really excited. I’ve worked really hard … and it is really exciting to be in the fourth round,” said Dellacqua in her post-match interview on court.

“I am just healthy. And I’m happy. When I am happy, I can play some good tennis.”

Clearly playing with great confidence and the beneficiary of being seeded at a grand slam for the first time, Dellacqua scrambled for every point and hit 26 winners to wear down her opponent in just under two-hours.

It was a nervy start for the left-hander, who also recently became a mother, serving a double-fault on the first point of the match and having to save a break point in the opening game.

Having been trounced by Pliskova in their only previous meeting it looked like the world No.42 could again have Dellacqua’s measure. However it was the 29th seed who grabbed the only break of the first set in the fourth game with an unplayable cross-court backhand pass.

Dellacqua surrendered the second set but took her game to another level in the third, jumping to an early lead, before holding her nerve to serve it out.

The win will see her play Flavia Pennetta for the chance to move into her first ever grand slam quarter-final, with world No.1 Serena Williams the likely opponent for the victor.