FRENCH Open champion Garbine Muguruza insists keeping a cool head will be the key to her challenging for the Australian Open title.

Muguruza, seeded seventh in Melbourne, eased past Anastasija Sevastova 6-4 6-2 on Friday to reach the last 16.

The Spaniard was predicted to become a multiple Grand Slam winner after her triumph at Roland Garros last year but second round exits at Wimbledon and the US Open have halted her momentum.

She appears ready to go deep again here with her victory over Sevastova setting up a fourth round meeting with Romanian Sorana Cirstea.

The winner is likely to play defending champion Angelique Kerber in the quarter-finals.

“I think I’m calmer if that makes sense,” Muguruza said. “I’m a little bit further from that emotional craziness when you, like, lose a point, you get upset a little bit.

“So I’m taking that a little bit from a distance, trying to analyse less, just go for the next point, keep in mind only positive messages.”

Kerber continued her title defence with a routine win over Kristyna Pliskova, the twin sister of Karolina, whom Kerber beat in the final at the US Open in September.

Kristyna Pliskova did not carry the same threat as her sibling, however, as Kerber sealed a 6-0 6-4 victory and will now go up against American Coco Vandeweghe.

Vandeweghe pulled off a surprise win against Eugenie Bouchard although she stopped short of declaring it one of the best results of her career. “This one isn’t that high for me,” Vandeweghe said.

“It was kind of expected in my mind to get the win and to get the victory and to move a step closer to achieving what I want to achieve for this year and also this tournament.”

Venus Williams has also gone through, along with eighth seed Svetlana Kuznetsova.