Barty took the first set 6-3 with typically combative, speedy play and Williams had it all to do to turn the match around.
Williams welcomed daughter Alexis Olympia Ohanian Jr in September past year with husband Alexis Ohanian, and she has previously told of the life-threatening health complications that arose during the birth.
As a result of that embolism, her coughing also popped open her c-section wound - at which point they also found a large hematoma (also clotted blood) in her abdomen. And I don't want to get there. Everything is allowed. Because once she gets her engine going, the lack of fitness. the long 15-month absence. the world ranking (451 at the start of the tournament). the improbability of it all. everything, goes out of the window.
Meanwhile, Williams, 36, made headlines with her tennis in a 7-6, 6-4 win and for her outfit.
While Williams loved the bond breastfeeding allowed her to share with Olympia, she said she also missed certain things.
"I have been really enjoying it".
"My husband is Armenian, I am learning a lot about Armenians, I am an honorary Armenian", the holder of 39 Grand Slam titles said on the sidelines of French Open, according to Ubitennis, an Italian tennis website". She needs to win five more matches, and it only gets more hard from here.
"I am so happy to be back here". I want to be able to just do my best and one day tell my daughter that I tried my best.
A fifth ace of the contest won her the set.
In an Instagram following the match, Williams dedicated her first time back on the court to all the moms out there.
As many have been before her, Barty began to look overawed by the force of Williams' personality.
"I feel like everything else will fall into place".
Whatever happens over the next two weeks, Williams insists her family priorities have eased the expectations on her as a player.