MELBOURNE, Australia -- Serena Williams is back in the Australian Open's third round alongside Naomi Osaka with both seeing off their opponents in a little over an hour on Wednesday.
Second-seeded Simona Halep, meanwhile, narrowly averted an early exit in the night matches, coming back from 5-2 down in the third set to beat No. 72 Ajla Tomljanovic of Australia 4-6, 6-4, 7-5.
Williams, owner of an Open era-record 23 major singles championships, moved on by grabbing the last seven games to beat 99th-ranked Nina Stojanovic of Serbia 6-3, 6-0.
Osaka beat former top-five player Caroline Garcia 6-2, 6-3 in an impressive showing.
Williams saved all three break points she faced, hit a half-dozen aces and compiled 27 winners with just 11 unforced errors.
"I wasn't thinking so much in the second set as I was in the first,'' Williams said. "I kind of just let go and see what happened.''
The 39-year-old American has won the title in Australia seven times, but her loss to Qiang Wang in the third round in 2020 was Williams' earliest exit at Melbourne Park in 14 years.
This time, Williams will try to go further with a win against Anastasia Potapova, a 19-year-old Russian who was the junior champion at Wimbledon in 2016 and currently is ranked 101st. Potapova has yet to win a tour-level title and will be making her debut in the third round at a major tournament.
Osaka will face No. 27 seed Ons Jabeur after her brilliant performance against Garcia.
"It felt great, I haven't played a night match in a long time," she said after.
"Staying focused throughout the entire match, it's hard to play opponents like her because you never know what she is going to do or how hard she is going to hit."
Osaka is on a 16-match win streak, with her last loss coming in a Fed Cup match last February. She has had two walkovers since the WTA Tour resumed in August, including last week before the semifinal of the Gippsland Trophy warm-up tournament.
Halep hadn't lost to a player ranked as low as Tomljanovic since her second-round defeat to No. 116 Taylor Townsend at the 2019 US Open.
Halep struggled to find her range with her groundstrokes, committing 37 unforced errors. The two players combined for 15 service breaks.
"I expected she's going to play hard and very strong," Halep said. "I expected it would be a difficult match, but it was more than I thought. I'm really happy I can smile now."
Halep, a two-time major champion, is closing in on her 100th Grand Slam main draw win. With the victory over Tomljanovic, she's now 98-38.
Also Wednesday, former US Open champion Bianca Andreescu's comeback from injury stalled when she was beaten by crafty veteran Su-Wei Hsieh of Taiwan, 6-3, 6-2.
Seeded eighth, the 20-year-old Canadian seemed befuddled by the 35-year-old Hsieh's unorthodox game, which includes a two-handed forehand and an unpredictable mix of pace and placement.
"She can literally redirect any single ball you give her,'' Andreescu said. "She can change the rhythm. I can change the rhythm too, but she's on another level, at least today.''
It didn't help that Andreescu served poorly, losing 17 of 23 points on her second serve. She was broken six times and fell to 1-for-3 in the second round at Grand Slams, with the lone win coming during her run to the US Open title.
Andreescu said she felt pleased to see her "fighting spirit" is still there but acknowledged the buildup to the year's first major, with players having to quarantine, made it somewhat difficult for her.
"After my first round, I thought I would feel more exhausted, but I felt amazing," she said. "Also, today the weather was a bit tricky. Being in the heart of quarantine, I could have had those extra two weeks of like being in the heat and getting used to sweating and all of that."
Hsieh is ranked 71st and has a history of inconsistency. But she's 8-2 against top-10 players, including two wins over the reigning world No. 1 -- Simona Halep at Wimbledon in 2018, and Osaka at Miami in 2019.
"It's strange. I normally feel more excited to play with better players," Hsieh said.
Two-time Wimbledon champion Petra Kvitova joined Andreescu as the second top-10 women's player to fall in the second round.
The ninth-seeded Kvitova was beaten by Romania's Sorana Cirstea 6-4, 1-6, 6-1. Kvitova reached the 2019 Australian Open final, losing to Naomi Osaka. She had also reached the fourth round or better at five of the past six Grand Slam tournaments.
Kvitova had 44 unforced errors against Cirstea to just 21 winners.
Another Canadian mounting a comeback also lost. Rebecca Marino, a former top-40 player competing in a major tournament for the first time in eight years, was beaten by No. 19 seed Marketa Vondrousova 6-1, 7-5.
Marino had been sidelined with depression and then a serious foot injury.
French Open champion Iga Swiatek beat Camila Giorgi 6-2, 6-4 and advanced along with No. 7-seeded Aryna Sabalenka.
Ann Li, a 20-year-old American, reached the third round for the second major in a row by beating Alize Cornet 6-2, 7-6 (6).
Li, who is ranked 69th, made her Grand Slam debut in Melbourne a year ago and reached the third round at the US Open. She reached her first WTA final last week at the Grampians Trophy by winning three matches. The final was called off for scheduling reasons.
Also Wednesday, two-time major winner Garbine Muguruza scored a 6-3, 6-1 win over Liudmilla Samsonova of Russia. Muguruza has been in impressive form since the start of the year, reaching the final of last week's Yarra Valley Classic warm-up tournament with the loss of just 10 games. She next faces Zarina Diyas of Kazakhstan.
Information from The Associated Press was used in this report.