Serena Williams overcame a sluggish start to beat Anastasia Potapova and reach the Australian Open fourth round.
However, the American had trailed 5-3 in an error-strewn first set, and she had to save two set points before dialling back in to win.
She faces seventh seed Aryna Sabalenka for a place in the quarter-finals.
“I came out of the blocks not like I have been before,” said the 39-year-old, who had dropped only five games in her previous two matches.
“But it’s all about surviving and playing better every round.”
She will face a tough test against big-hitting Belarusian Sabalenka, who beat American Ann Li 6-3 6-1.
This is the last day that crowds will be in attendance at Melbourne Park before the state of Victoria enters a five-day lockdown. on Saturday.
Eleventh seed Williams, bidding for a record-equalling 24th Grand Slam title, came through 7-6 (7-5) 6-2 against the 101st-ranked Russian.
Up to 30,000 fans had been allowed in each day but the tournament will continue behind closed doors after an outbreak of coronavirus in a hotel.
Last year’s finalist Garbine Muguruza also advanced, needing just 58 minutes to beat Kazakhstan’s Zarina Diyas 6-1 6-1.
Spaniard Muguruza has lost just 10 games in her opening three matches and will play either favourite Naomi Osaka or Ons Jabeur of Tunisia next.
Taiwanese Hsieh Su-wei reached the fourth round for the third time in her career with a 6-4 2-6 7-5 victory over Sara Errani of Italy.
Hseih, who beat eighth seed Bianca Andreescu in the second round, trailed 5-3 in the decider before winning four successive games to advance.
She will play Czech Marketa Vondrousova next, after the 19th seed beat Sorana Cirstea of Romania 6-2 6-4.