Australian Open overnight: Thiem and Serena dig deep, fans banned on Day 5

The first Grand Slam of 2021 is in full swing. Each morning, we'll review the action you may have missed Down Under. Here's what happened overnight on Day 5 of the Australian Open.

Top story: Injury could force Djokovic to withdraw

Novak Djokovic doesn’t know if he will be able to play his next match at the Australian Open.

The defending champion said he has a torn muscle after taking a fall in his third-round win over Taylor Fritz and doesn't know if two days will be enough time to recover.

He beat Fritz 7-6 (1), 6-4, 3-6, 4-6, 6-2 to advance to a fourth-round match against Milos Raonic on Sunday.

He says he’s “I’m very proud of this achievement tonight,” in overcoming the injury to win. “Let’s see what happens.”

Serena digs deep in 3rd round

Serena Williams needed a bit of everything, including one on-the-run, back-to-the-net, no-look, over-the-shoulder shot, to get past a challenge at the Australian Open from a player who’s 20 years younger than she is.

A year after a surprising loss in the third round at Melbourne Park, Williams managed to get past that stage by beating Russian teen Anastasia Potapova 7-6 (5), 6-2.

Potapova served for the opening set at 5-3. But the 2016 Wimbledon junior champion double-faulted five times in that game, including twice on set point.

Williams — who has won seven of her 23 Grand Slam singles titles in Australia — then trailed 5-3 in the tiebreaker. But she took the next four points, the last on a 21-stroke exchange that ended with Potapova putting a forehand into the net.

Potapova, 19 and ranked 101st, edged ahead by breaking to begin the second set, but the 39-year-old Williams broke right back with the help of that remarkable get on a lob. She smiled at herself, assuming the point was over — and then laughed upon realizing she won the point, because Potapova responded by missing an overhead into the net.

Fans banned after COVID-19 outbreak

Fans will be banned from attending the Australian Open at Melbourne Park for five days from Saturday because of a COVID-19 outbreak at a quarantine hotel.

Victoria state Premier Daniel Andrews on Friday announced a five-day lockdown starting a minute before midnight local time, imposing new restrictions that allow residents to only leave home to shop for essential supplies, care and caregiving, exercise and essential work.

The tournament will be allowed to continue as a workplace, but without crowds.

Schools will be closed Monday through Wednesday, and there will be no gatherings for weddings or religious services.

Fans arriving at Melbourne Park on Friday before the announcement were instructed at the entrance gates to maintain social-distancing, apply sanitizer to their hands and pull their masks up over their noses.

The Australian Open was the first Grand Slam tournament in a year to allow sizable crowds.

After the COVID-19 outbreak became a pandemic, Wimbledon was canceled, fans were not allowed at the U.S. Open and the number of spectators at the French Open was heavily restricted.

Under the initial plan for the Australian Open, the government allowed up to 30,000 people daily at Melbourne Park, or about 50% of capacity. The biggest daily attendance in the first four days was 21,010 on Thursday.

The lockdown is set to end at midnight next Wednesday, when decisions on restrictions will be made.

Thiem roars back to beat Kyrgios

Dominic Thiem has come all the way back from two sets down against the talented and tempestuous Nick Kyrgios to win their third-round match at the Australian Open.

The third-seeded Thiem did his best to ignore a rowdy partisan crowd supporting Australia’s Kyrgios and pulled out the 4-6, 4-6, 6-3, 6-4, 6-4 victory.

Thiem was the runner-up to Novak Djokovic at Melbourne Park a year ago and then went on to win his first Grand Slam title at the U.S. Open in September. Thiem was the first man in 71 years to come back from a two-set hole in the final in New York and now he’s overturned that sort of deficit again.

Thiem will face Grigor Dimitrov for a spot in the quarterfinals.

Osaka overcomes unforced errors

Naomi Osaka is back in the fourth round of the Australian Open for the first time since her title run in 2019.

Osaka overcame 28 unforced errors and saved six of seven break points she faced in a 6-3, 6-2 win over 27th-seeded Ons Jabeur of Tunisia on Friday.

“I was really nervous and scared because I didn't know if she was going to hit a drop shot on any ball," Osaka said of playing Jabeur for the first time.

Osaka was stunned last year in the third round at Melbourne Park by then-15-year-old Coco Gauff. She has looked solid so far this year, dropping just 13 games in her first three matches.

Osaka and Serena Williams are the only two former Australian Open champions remaining in the draw after the losses by Sofia Kenin, Victoria Azarenka and Angelique Kerber.

She next faces another in-form player, two-time major winner Garbiñe Muguruza, who has lost even fewer games (10) en route to the fourth round.

Swiatek sets up meeting with Halep

French Open champion Iga Swiatek ran her Grand Slam winning streak to 10 matches by beating Fiona Ferro 6-4, 6-3 at Melbourne Park.

The 15th-seeded Swiatek is into the fourth round at the Australian Open for the second year in a row.

She can get to her first quarterfinal in Australia if she eliminates two-time major champion Simona Halep next.

Swiatek is a 19-year-old from Poland who had never won a tour-level title until claiming a Grand Slam trophy at Roland Garros in October.

Schwartzman ousted by Russian qualifier

Eighth-seeded Diego Schwartzman has been eliminated in the third round of the Australian Open by Aslan Karatsev, a qualifier from Russia ranked 114th and making his Grand Slam debut.

By far the biggest victory of the 27-year-old Karatsev’s career came via a hard-to-believe margin of 50-5 in total winners and a lopsided score of 6-3, 6-3, 6-3.

He is only the fifth man since 2000 to reach the round of 16 in his first appearance at a major championship. He’s also the first qualifier to get that far at Melbourne Park since Milos Raonic a decade ago.

Karatsev never had beaten a player ranked higher than 48th. He now will meet another seeded player with a quarterfinal berth at stake — No. 11 Denis Shapovalov or No. 20 Felix Auger-Aliassime, who were scheduled to face each other later Friday.

Schwartzman was a semifinalist at last year’s French Open and entered Friday with a 9-0 record against qualifiers in Grand Slam matches.