Ukraine tennis star Elina Svitolina said she thought "something bad had happened" when a French fighter jet flew over Roland Garros on Wednesday, breaking the sound barrier.
The thunderous noise that panicked residents of Paris was caused by the sonic boom, police in the French capital said.
The military said the jet had been scrambled to go to the aid of another aircraft that had lost radio contact, and was authorised to travel at supersonic speed.
"Yeah, I heard it. I was a bit worried because I thought something bad happened," said Svitolina after defeating Mexico's Renata Zarazua 6-3, 0-6, 6-2 on the tournament's showpiece Court Philippe Chatrier.
"I looked at the chair umpire. He was little bit shocked as well because you never know these days what can happen, what's going on.
"Yeah, it was the airplane, so it was very strange, very loud, like something big dropped."
The noise, which was heard all over the city and neighbouring suburbs and shook windows, rattled Parisians already on edge after a knife attack outside the former offices of satirical weekly Charlie Hebdo last week that the government has called an act of terror.