Tennis - Australian Open - Rod Laver Arena, Melbourne, Australia

Fourth seed Elina Svitolina came through a first set wobble to set up a third-round meeting with 15-year-old compatriot Marta Kostyuk with a 4-6 6-2 6-1 victory over Katerina Siniakova on Wednesday.

Ukrainian Svitolina was forced to fight back after conceding only her second set in seven matches this year but ultimately found a way to get past her Czech opponent as the temperatures soared on Rod Laver Arena.

“I thought I was going to melt today, it was not easy and I was struggling a bit,” said the 23-year-old right-hander.

“Hopefully I can recover. I can’t wait to get into an ice bath.”

Firming as one of the favourites in a wide open race for the Melbourne Park crown, Svitolina will next face world number 521 Kostyuk, the qualifier who doubled down on her maiden grand slam victory on Monday with a 6-3 7-5 win over local Olivia Rogowska.

Her first set performance against Siniakova clearly sounded a warning to Svitolina about letting kind of complacency creep into her head as she earned six break points but failed to convert a single one of them.

World number 59 Siniakova, who also took Svitolina to three sets at the U.S. Open last year, really went for her shots, hitting 11 winners, and it was she who managed to get the upper hand in an arm-wrestle of a 50-minute set.

“I think she was playing great in the first set and I gave her this one break and this chance to dominate and play well,” said Svitolina, who gave up the set with a miscued backhand.

“It was my kind of mistake and maybe next time I’ll be more focused.”

Svitolina has backed up a fine 2017 with some impressive form already this year, not least her run to the title at the Brisbane International, and finally got her first break at the eighth attempt to go 2-0 up in the second set.

Siniakova never gave up but was not the same threat after a seven-minute medical timeout in the second set and Svitolina claimed the victory with an unreturnable serve after two hours and 14 minutes.

“Of course winning in Brisbane and having such a good year in 2017, it’s great,” she said.

“But, you know, it’s a grand slam and every opponent is very tough and everyone deserves to win and be here. Yesterday, we saw there are no easy games here.”