"And, yeah, today is one of those days where, regardless of the statistics, how I felt on court, it doesn't matter - we've got an opportunity to come out here a couple days time in round two".
Williams had all sorts of trouble in the opening set, compiling 12 unforced errors.
After the success of raising the volume, Williams continued to channel her loud energy into every point and the intensity became too much for the 17th seed.
Williams, 36, had to fight for this one, particularly in the first set in which she lost the first three points of the tiebreaker.
"Our prices are practical, our fabrics are practical, but [the customer] is also a smart woman, they're a smart girl", Williams told the Los Angeles Times.
Seemingly unnerved by the occasion, Barty broke the 23-times major champion early in the second set to surge further ahead before Williams willed her way back into the enthralling contest on Court Philippe-Chatrier. "What she's done to be able to get back.is a pretty incredible thing".
What she lacked on Thursday was a more reliable first serve (she put just 55 percent into play) and a more reliable forehand under duress as Williams started to find her range and attack.
The 36-year-old American, who became a mother on September 1, grabbed four consecutive games over a span of less than 15 minutes to lead 4-1 in the second set, which soon enough would be hers.
Beyond that, Williams wanted her comeback to mean something to moms like her who are trying to get back in the game (literally and figuratively) after giving birth.
"I feel like a warrior wearing it, a queen from Wakanda [a reference to the Black Panther movie] maybe", she said.
But her attire was the main focus at Roland Garros as Williams took to the court in an all-black Nike "catsuit".
Williams let out a spectacular roar after a backhand service return victor, and a rather uncertain crowd took that as a cue to wake up. Love you all!' she said. "Long enough for you to be able to watch me, cheer me on, and be proud of me".
The only consolation for Pliskova, the twin sister of world number six Karolina, was finishing with 15 aces, the most hit against Williams since such records began to be kept in 2008. Williams beat Pliskova's twin sister, Kristyna, in the first round in Paris.
It turns out Williams herself was going for a little bit of the superhero look.
"That's a tough one for Serena; I honestly wouldn't expect her to win that", said Pat Cash, the former Wimbledon champion who is coaching the American player Coco Vandeweghe.
"I think she's not quite at the level she was when she was at her best, but that's normal". Looking for breaking news, videos, Olympic and Paralympic team bios all at your fingertips?