Italy’s Flavia Pennetta is the first woman into the Australian Open quarter-finals following a three-set defeat of German ninth seed Angelique Kerber.

In defiance of their rankings, and thanks to a first set that gave her a mental edge, Pennetta, the 28th seed, won 6-1 4-6 7-5.

“The first set was one of the best I’ve played for a long time,” Pennetta said.

The victory also proved to be one for experience over youth for the 31-year-old who is playing in her 42nd grand slam singles championship.

“I’m a little old now, so I enjoy it more,” she said.

Despite being closer to the end of her career than the beginning, Pennetta’s run is her best in 10 appearances at the Australian Open and follows her best-ever grand-slam performance when a semi-finalist at last year’s US Open.

Pennetta’s domination of the opening set left Kerber out of sorts and ultimately put her out of the tournament.

Although she levelled in the second, Pennetta again asserted herself in the third, making a shaky attempt to serve for the match at 5-4 before claiming victory at her second opportunity minutes later.