Pliskova had closed out the first set after wasting several opportunities.

Simona Halep won nine games in a row to breeze past Karolina Pliskova and set up a mouthwatering Australian Open semi-final against former champion Angelique Kerber.

World number one and top seed Angelique Kerber suffered an unexpected defeat to Estonian qualifier Anett Kontaveit in the second round of the Internazionali BNL d'Italia in Rome.

Defending champion Agnieszka Radwanska lost her first match of the WTA Finals in Singapore, with Svetlana Kuznetsova surviving match point to score the upset.

Karolina Pliskova is through to her first grand slam semi-final after easing past Croatia’s Ana Konjuh at the US Open last night.