“It’s OK,” she said. “It’s a war wound. I think it happens to everyone, but I have never busted it wide open like that.”
Williams lifted her tempo on the biggest points, including when she finally won an 18 minute game to open the second set en route to a 6-2, 6-0 win over Garbine Muguruza.
She later combined with sister Venus to win in the first round of doubles, showing no signs of trouble with the ankle.
The top-ranked Victoria Azarenka pranced into Rod Laver Arena for the first match of the day, and said she is starting to find some rhythm after beating Eleni Daniilidou 6-1, 6-0 in 55 minutes.
“I felt like I’m back into the competitive mode,” Azarenka said.
The No. 94-ranked Daniilidou only won 10 points in the first set and was shut out in the second despite having triple break point in the fourth game.
The heat did not seem to bother 42-year-old Kimiko Date-Krumm, who advanced 6-2, 7-5 over Shahar Peer of Israel. Date-Krumm became the oldest woman to win a singles match at the Australian Open.
Other women advancing included former No. 1-ranked Caroline Wozniacki, No. 14 Maria Kirilenko, No. 16 Roberta Vinci, No. 20 Yanina Wickmayer and Elena Vesnina, who beat No. 21-seeded Varvara Lepchenko of the US 6-4, 6-2.