The meeting took place in Melbourne.

It lasted 2 hours 14 minutes and ended with the score 3: 6, 7: 6 (7: 5), 2: 6.

In the quarterfinals, Sobolenko and Mertens will face Suko Aoyama and Ena Shibahara from Japan.

Earlier, Williams beat Sobolenko and reached the quarterfinals of the Australian Open.