She had deliberately held back from a return, skipping Rome and Madrid, in order to make sure she was ready to compete on what is her least natural surface, training at the academy belonging to her coach, Patrick Mouratoglou.
Williams wore a black body suit with long leggings and a red waistband for her first-round French Open match at Court Philippe Chatrier.
Fans too were outraged by the decision and one on Twitter, with the moniker "Cedric", suggested the TV snub might be because the French public have never warmed to the three-time Roland Garros champion.
Williams said the bodysuit made her feel like a "queen of Wakanda".
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.
As French organisers rigidly use WTA rankings to determine their seedings she is the most risky of floaters.
"I was struggling to get in a little rhythm because there was so much acing, so many aces going on".
Florida State Defeats Louisville In ACCBC Title Game
The entire 64-team bracket and national seeds will be unveiled during Monday's selection show, which airs live on ESPNU at 9 a.m. And senior catcher JJ Schwarz also sat out the conference tournament with a hand injury.
"She's playing unbelievable, and she's had such an wonderful year last year and this year as well", said the three-times French Open champion and former world No.1.
"I did everything possible with my team to get us in a position to be able to play today".
Azarenka also has a child and says that coming back from pregnancy is different from coming back from a tennis injury.
An increasingly unpredictable set saw Williams break again, the third break in a row and fifth in the set overall.
"I'm happy to have won a match here and I'm just taking it one day at a time".
Williams will play her second-round match against 17th-ranked Ashleigh Barty, who is very impressed by her opponent's comeback: "What Serena's done to be able to get back, along with Azarenka as well, and a lot of the other girls who are coming back after pregnancy, is a pretty awesome thing".
She admitted the suit also had some functionality to it, after she suffered through blood clots after Olympia's birth. "I'll be excited to go out and see what I can do".