It was her first major tennis match since triumphing at the 2017 Australian Open while eight weeks pregnant- and she won while wearing a "Black Panther"-style catsuit that made her feel "like a warrior princess" from Wakanda, the fictional nation from the Marvel Comics film".
"Are you here to compete, or are you here because you feel you can win the tournament?" a journalist asked her after her straight-sets victory over Kristyna Pliskova on Tuesday.
Playing her first Major since the birth of daughter Alexis Olympia on September 1, she is determined to show that the competitive fire still burns bright.
However, she gave a stinging response to the doubters on Tuesday even if her win over the 70th-ranked Pliskova tested the American.
Serena Williams has experienced both racism and sexism in her career.
"We all know how I feel about the cold shoulders", Williams tells The Post of last year's beloved shoulder cutout trend. "I take it one day at a time".
Her first point was a dropshot to chase, and it was the initial indication that her movement was definitely improved from her performances in America.
'You know, no matter the score, I still knew that I produce quite solid tennis in order to get myself in a winning position, and I felt there is no reason that I couldn't get that back'.
"I missed Roland Garros so much, I missed the battle". I have been wearing trousers in general a lot when I play so I can keep the blood circulation going.
A three-time champion at Roland Garros, Williams, 36, had not played a competitive match on clay this season ahead of her first-round match against Pliskova, who had 15 aces.
"I have been really enjoying it".
Williams teammed with sister Venus for a 4-6 6-4 6-1 win over Japanese pair Shuko Aoyama and Miyu Karto, while Barty - a finalist with Casey Dellacqua a year ago - and American Coco Vandeweghe suffered a disappointing 2-6 6-4 6-4 loss to Croatians Donna Vekic and Darija Jurak.
"But there was no beer pong", Williams added, in relation to reports that guests at the reception played a popular drinking game in which you throw ping pong balls towards other people's glasses, obliging them to gulp down any drink with a ball in it. "It definitely has little functionality to it. It just kind of expands that, and I really, really embrace it".
Williams will face Australia's Ashleigh Barty in the next round, and will be hoping to draw on the same powers bestowed by her new catsuit. I think Serena is also in a very different place and just what an opportunity.