Earlier in the day, Petra Kvitova's first tournament since being injured in a knife attack at her home was brought to an early end.
Serena recently revealed she had actually accidentally announced her pregnancy. To be clear, she didn't directly say, "My sister is having a girl", but she definitely spoiled if her younger sister will soon be mom to a daughter.
"She's going to call me 'favorite aunt, '" Venus Williams said.
Resuming his quest for a 10th title in Paris, Rafael Nadal later joined Djokovic and Muguruza without dropping a set, dispatching Robin Haase 6-1, 6-4, 6-3 in one hour and 49 minutes.
"I love being here and I love playing on this court", Williams, who is playing her 20th French Open, said afterwards.
LeBron James breaks Michael Jordan's playoff scoring record
That's all I can give you right now because I'm happy and I don't want to be stressed. "You're going to have ups and downs". He can read situations. "It's a pretty hard thing to swallow, so I'm pretty down". "I'm not a scorer", James said.
She pulled back level but was edged out in another tie-break, bouncing her racket in annoyance after serving a double fault on match point.
First on court on a bright and breezy Wednesday was No10 seed, Venus Williams, who will turn 37 in a fortnight's time.
Caroline Wozniacki continued her good form as the former world number one double-bageled Francoise Abanda 6-0, 6-0. "I don't know how well I'm going to do, because I don't know what to do".
The Williams sisters sure know how to make announcements about major life events in the most nonchalant way. She has a will that is also completely unusual. "I never see any limits for her and put any limits to her, because that would be wrong". It's fantastic. It's something very special that if you love the sport you can do it.
"I didn't tell a lot of people, to be quite honest, and I'd been saving it", she added.
- Celtics star Isaiah Thomas unsure if he'll need hip surgery
- Manchester terror attack: Police investigating 'network' over concert bombing
- Reformists sweep Tehran municipal vote as Rouhani wins Iran
- Djokovic and Nadal could meet in French Open semifinals
- LeBron James overtakes Michael Jordan as Cavaliers reach National Basketball Association finals again
- Father of Accused Manchester Attacker Says His Son Is Innocent
- Muguruza wins battle of the former French Open champions
- Mila Kunis and Ashton Kutcher make surprise appearance on The Bachelorette
- Three reasons why Tom Rogic must start the Scottish Cup Final
- Blues rocker Gregg Allman dies at 69