Caroline Wozniacki admits she resorted to dreaming to get through Sydney’s heatwave in her marathon three-set loss to Barbora Strycova.

The former world No.1 was attempting to end a run of seven Sydney visits without getting past the quarter-finals at the Sydney International, but fell 7-5 6-7 (7-6) 6-4.

Almost a third of the three-hour, 19-minute epic was played in over 40-degree heat.

Both players were treated for foot injuries during a gruelling second set on Ken Rosewall Arena, where they also battled mental demons at Homebush.

“It was brutal out there, and it was really hot. But you know, you just try and think like you’re on a beach drinking pina coladas,” Wozniacki said after the match.

“That’s basically your train of thought. You know that it’s the same for both players, so I was just trying to mentally just try and keep cool. But it was really, really hot out there.”

“I thought we played actually some ready good tennis as well, considering all these conditions.”

Wozniacki looked on track to end her barren run at Homebush when she battled back from 5-2 down in the second set, and then 5-0 in the tiebreaker, to force a third set.

The Dane broke the world No.19 twice in the decider, but gave up three games of her own and will now recuperate ahead of next week’s Australian Open.

“On the positive side of things, I can eat whatever I want now because I have burned a lot of calories today. I’ll definitely have an ice cream, for sure,” she said.

Strycova is the first woman through to the semi-finals on day four and will now meet the winner of second-seed Agnieszka Radwanska and qualifier Ying-Ting Duan.

The winner of Eugenie Bouchard and Anastasia Pavlyuchenkova will face the other victor between Daria Kasatkina and Johanna Konta.