Casey Dellacqua’s bold bid to reach her maiden grand slam quarter-final has come to an end at the US Open in New York.

Italy’s classy 11th seed Flavia Pennetta won a fiercely contested opening set before running away with a 7-5 6-2 fourth-round victory at Flushing Meadows on Monday.

After reaching the last 16 at two majors in a calendar year for the first time, Dellacqua was striving to enter more uncharted territory and set up a likely blockbuster quarter-final with Serena Williams.

But Pennetta, now a five-time Open quarter-finalist who made the semi-finals last year, proved too hot.

The first set proved key in more muggy conditions at Arthur Ashe Stadium.

In a glimpse of the torrid battle to come, Dellacqua fought off three break points in the opening game to hold after a seven-minute serving game.

Pennetta also had to save a break point to hold for 1-1 before striking first blood with a powerful backhand return down the line in the third game.

Dellacqua broke right back to make it 2-2 as the Australian’s heavy groundstrokes forced Pennetta to frame two forehands into the stands.

Pennetta claimed her second break when Dellacqua dumped a forehand into the net to fall behind 4-3, but the Aussie underdog hit back immediately once more with some impressive defence inducing another forehand shank from the Italian.

The key game in the set came with Pennetta serving at 4-5 when Dellacqua, pressing hard for a third break, twice stood within two points of taking the opening set.

Pennetta, though, held firm, then grabbed the decisive break herself before serving out the hard-fought set after 50 minutes.

Dellacqua was under the pump again early in the second set, dropping serve as Pennetta established a 2-0 buffer.

The writing was on the wall when Dellacqua coughed up her third double-fault and then sprayed a wild forehand wide to hand Pennetta the double break.

Pennetta converted her big advantage after one hour and 20 minutes to end Australia’s interest in the singles for another year.

Despite the defeat, Dellacqua will depart Flushing Meadows with a career-high ranking close to the world’s top 25 – a year after dipping outside the top 200 – and on track to secure a first-ever seeding at the Australian Open in January.