Johanna Konta sat on a towel along the baseline, her racket resting by her feet, an ice bag under each arm, chest heaving.
Fans murmured with concern in the stands and her opponent stood next to her chair, unsure what to do.
Asked later how she was feeling – physically – the 25-year-old Brit replied instead: “I’m feeling a little embarrassed.”
Konta had keeled over while trying to start her service motion, one point from losing the second set of her US Open match.
Down on the court for 7 1/2 minutes, she came back out to hit one serve into the net for a set-ending double-fault, after which she headed to the locker room to change her sweat-drenched outfit.
Then the 13th-seeded Konta returned to win the third set for a 6-2, 5-7, 6-2 second-round victory over Tsvetana Pironkova that lasted more than 2 1/2 hours.
With Konta serving at 5-6 in the second, the game dragged on for 10 minutes, including four deuces and four rallies of at least 10 strokes. After the last and longest of those – an 18-shot point – Konta missed her first serve, then bent over as she attempted the second.
She went down to her knees, gasping for breath. Her heart was racing, her body shaking.
Pironkova came to the net; the chair umpire rushed over. A ballperson laid a towel next to her, and the chair ump handed her several bags of ice.
Four minutes passed before medical staff got to Konta, who had rolled onto her back by then. They checked her pulse and her blood pressure, held a thermometer to her ear and a stethoscope to her back.
Pironkova sat in her chair, staring off blankly, legs bouncing.
“Because I’d experienced it once before, I didn’t start crying,” she said.
Focused on controlling her breathing, Konta put together an efficient third set to move on.
“I just played with what I had,” she said.
All the delays – the medical timeout, the toilet break – were within the rules, Pironkova agreed. That didn’t make it any less maddening.
“What wasn’t fair to me was what happened after that – the toilet break,” Pironkova said.
“Because with that toilet break the match was stopped for just too long. … Today I am not very happy about the rules.”
Konta is drawn to play Swiss 24th seed Belinda Bencic in the third round.