The Paraguayan has never won a WTA singles title. She has never cracked the top 70 in the world rankings. She has never even beaten a top 10 player.
So it was little wonder she seemed to be shrieking what sounded like "Oh my God" every time she made contact with the ball as she pushed and pushed eighth seed Petra Kvitova to the edge of defeat in their first round encounter on Court Philippe-Chatrier at the French Open on Monday.
With the 15,000-seat arena not even half full, the 87th-ranked Cepede Royg's cries echoed louder and louder as she got closer to what would be the biggest win of her career.
The fact that Kvitova was riding high on an 11-match winning streak on clay would have made the upset even more remarkable as the Czech had been installed as one of the title favourites following her claycourt wins in Prague and Madrid.
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But as the Paraguayan stood three points from victory at 5-4 and 0-15 ahead on Kvitova's serve in the third set, the Czech's famed survival instincts kicked in.
Kvitova, who suffered career-threatening injuries on her playing left hand after being attacked in her home by a knife-wielding intruder in December 2016, unleashed three successive aces to stay alive.
She was soon saluting the crowd with a raised clenched-fist as she broke in the next game before wrapping up a 3-6 6-1 7-5 victory to set up a second-round meeting with Spain's Lara Arruabarrena.
"I was lucky today I made it," summed up Kvitova.
"It was really tough to break her serve. She hit almost everything."
While Cepede Royg has not made it past the first round of any major outside of Roland Garros, it was here in Paris 12 months ago that she reached the fourth round.
It was clear she was drawing on that experience on Monday as she unsettled Kvitova in both the first and third sets with her bone-rattling groundstrokes.
But the twice Wimbledon champion, who proved even her surgeon wrong by coming back to play top level tennis just five months after the attack, surged over the finishing line thanks to her nerves of steel.
"I'm not surprised she reached the fourth round last year. She really likes the conditions here and played very well. She didn't really miss much. It was pretty tough," said Kvitova.
While a dejected Cepede Royg was left to dwell on her near miss, there was at least one silver lining for her. The $46,000 first round losers' cheque finally tipped her over the $1 million dollar mark in career prize money.
(Reporting by Pritha Sarkar, editing by Christian Radnedge)
