Twenty-three time Grand Slam champion, Serena Williams, on Wednesday suffered a shocking defeat to rising Argentine star, Nadia Podoroska, in Rome at the Italian Open.

The World No.44 handed No.8 seeded Williams a defeat on her 1000th career milestone match in two rounds at the Internazionali BNL d’Italia.

Podoroska moved from heavy top spin forehands to adept sliding defence to upset Williams, 7-6(6), 7-5 in one hour and 58 minutes.

Reacting to the defeat, Williams said, “I’m not playing as many matches. I’m just doing a lot of training. So it’s actually really good to get out and to play some matches… My season doesn’t usually start this late on clay. But the training isn’t for nothing, so I know that it’s just a matter of time.”

“It’s tough to have a first match on clay. It was definitely kind of good to go the distance and to try to be out there, but clearly, I can do legions better,” Williams added.

“She has a good game, for sure, obviously. She’s very consistent. Overall, it was good for me to play such a clay court player on clay today, but it’s a little frustrating. But it’s all right. It is what it is.

“I have been training for months, but it feels definitely different on clay to make that last adjustment. Just filling out the game, finding the rhythm. Even sliding and confidence with that, with movement… That’s always like a little struggle in the first two matches, and then I’m raring to go,” she said.

Elsewhere, World No. 2 seeded Naomi Osaka’s clay-court nightmare continued as she lost 7-6 (7-2) 6-2 to American world number 31 Pegula in Rome.

The defeat of the four-time Grand Slam champion, 23, comes after a second-round loss at the Madrid Open earlier this month.