British 13th seed Johanna Konta felt “embarrassed” after recovering from a health scare at a humid U.S. Open on Wednesday to claim her place in the third round with a 6-2 5-7 6-2 win over Bulgaria’s Tsvetana Pironkova.

Konta was leading by a set but serving at set-point down in the second when she suddenly dropped to her knees, shaking and struggling to catch her breath as temperatures neared 88 degrees Fahrenheit (31 degrees Celsius).

After receiving extensive treatment, including ice bags, first from the umpire and later from a doctor, Konta dropped the set on a double fault.

But after a bathroom break between sets, the 25-year-old recovered in time to set up a third-round clash with Belinda Bencic of Switzerland.

“I am feeling a little embarrassed but I’m doing everything that I can to recover well to compete again on Friday,” said Konta, before disclosing that she had suffered a similar health scare four years ago.

“I was feeling the conditions and my own energy levels ... basically my heart rate spiked, I couldn’t really control my breathing and I started shaking ... that’s why I went down on the ground.

“Because I’d experienced it once before, I didn’t start crying. I don’t know if anyone’s had a panic attack, but that’s basically what it feels like except my muscles are shaking as well.”