"I heard she won love and love, so what kind of injury are we talking about?" she said.
Azarenka's win was sandwiched between matches on the same court involving two of the main contenders for the men's title. No. 3 Andy Murray won his first Grand Slam match as a major champion, beating Robin Haase of the Netherlands in straight sets, and No. 2 Roger Federer fended off Benoit Paire of France 6-2, 6-4, 6-1.
With a packed program on the center court, Williams was playing on the second of the show courts.
The 31-year-old Williams was leading 4-0 after 19 minutes when she fell awkwardly chasing a ball wide on her forehand side, putting both hands over her face.
She rolled from her back to her hands and knees, where she stayed for several minutes before she was helped to her feet. The 15-time major winner started limping before easing into a walking stride as she made her way to her court-side chair to have her already heavily taped ankle treated and then re-taped.
"I think I was really, really close to panicking because a very similar thing happened to me last year, almost on the same side, the same shot," Williams said. "So I almost panicked, and I thought, I can't do that. I just have to really remain calm and think things through."
Williams won the first point after the medical timeout, approaching the net to hit a cross-court winner, seemingly unfazed by the ankle. She hit two more forehand winners to go up 5-0, then called the trainer back to the court to adjust the taping on the ankle during the changeover. She had more treatment after winning the first set.
Williams winced slightly after jumping to hit an overhead in the third game of the second set and called the trainer out again to re-tape the ankle during the changeover, leading 3-0.