It's been three years since Serena Williams won a Grand Slam championship. Her drought without a title of any sort just ended, though, right before the start of the Australian Open.

Williams got back on the board a week ago at the hard-court event in Auckland, New Zealand, and her reaction upon clinching the victory -- head back, mouth open, arms held aloft -- indicated just how much it meant to someone who already owned 72 singles trophies, including a professional-era record 23 from majors.

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United States' Serena Williams reacts during a practice session ahead of the Australian Open tennis championship in Melbourne, Australia, Friday, Jan. 17, 2020. (AP PhotoLee Jin-man)

It's been three years since Serena Williams won a Grand Slam championship. Her drought without a title of any sort just ended, though, right before the start of the Australian Open.

United States' Serena Williams and her coach Patrick Mouratoglou react during a practice session ahead of the Australian Open tennis championship in Melbourne, Australia, Friday, Jan. 17, 2020. (AP PhotoLee Jin-man)

It felt like a significant development with main-draw play at the year's first major tournament beginning Monday (Sunday EST) at Melbourne Park. Williams, who is seeded eighth, is scheduled to face Anastasia Potapova of Russia in the day's second match in Rod Laver Arena, after defending champion Naomi Osaka takes on Marie Bouzkova of the Czech Republic, and before Roger Federer meets Steve Johnson of the U.S.

Switzerland's Roger Federer serves during a practice session ahead of the Australian Open tennis championship in Melbourne, Australia, Sunday, Jan. 19, 2020. (AP PhotoLee Jin-man)

And it made her the first woman in the professional era with at least one title in four decades: the 1990s, 2000s, 2010s and 2020s.

Spain's Rafael Nadal makes forehand return during a practice session ahead of the Australian Open tennis championship in Melbourne, Australia, Sunday, Jan. 19, 2020. (AP PhotoDita Alangkara)

Here are other things to know about the Australian Open, the year's first Grand Slam tournament:

Serbia's Novak Djokovic gestures during a press conference ahead of the Australian Open tennis championship in Melbourne, Australia, Sunday, Jan. 19, 2020. (AP PhotoDita Alangkara)

BIG THREE

Russia's Andrey Rublev poses with the trophy after winning the Adelaide International tennis final match in Adelaide, Saturday, Jan. 18, 2020. (AP PhotoJames Elsby)

Eventually, the Big Three's grip on tennis will subside. And eventually, some younger player will assert himself. Tennis' great guessing game right now is when those things will happen — and who'll be the first of the kids to win a Grand Slam title. Right now, there is a trio of young Russians pushing their way into the conversation: No. 4 seed Daniil Medvedev, who is 23 years old; No. 16 Karen Khachanov, also 23; and No. 17 Andrey Rublev, 22. Medvedev pushed Nadal to five sets in last year's U.S. Open final; Khachanov was a 2019 French Open quarterfinalist; Rublev's trophies this month at Doha and Adelaide made him the first man since 2004 with two tour-level titles before the Australian Open.

Japan's Naomi Osaka warms-up with her coach Wim Fissette during a practice session ahead of the Australian Open tennis championship in Melbourne, Australia, Sunday, Jan. 19, 2020. (AP PhotoAndy Wong)

WOZNIACKI'S EXIT

"You could see," Williams said, "the relief on my face."

United States' Serena Williams reacts during a practice session ahead of the Australian Open tennis championship in Melbourne, Australia, Friday, Jan. 17, 2020. (AP PhotoLee Jin-man)

United States' Serena Williams reacts during a practice session ahead of the Australian Open tennis championship in Melbourne, Australia, Friday, Jan. 17, 2020. (AP PhotoLee Jin-man)

It felt like a significant development with main-draw play at the year's first major tournament beginning Monday (Sunday EST) at Melbourne Park. Williams, who is seeded eighth, is scheduled to face Anastasia Potapova of Russia in the day's second match in Rod Laver Arena, after defending champion Naomi Osaka takes on Marie Bouzkova of the Czech Republic, and before Roger Federer meets Steve Johnson of the U.S.

The 38-year-old Williams had lost her previous five finals, including four at Slams -- at Wimbledon and the U.S. Open in 2018 and 2019. Maybe getting all the way to the finish line in Auckland will put her more at ease the next time she plays with a trophy at stake.

In addition to her first title of any sort since setting a professional-era record with her 23rd major at the 2017 Australian Open -- one more would equal Margaret Court for the most in tennis history -- it was also Williams' first since becoming a mother later that year.

United States' Serena Williams and her coach Patrick Mouratoglou react during a practice session ahead of the Australian Open tennis championship in Melbourne, Australia, Friday, Jan. 17, 2020. (AP PhotoLee Jin-man)

United States' Serena Williams and her coach Patrick Mouratoglou react during a practice session ahead of the Australian Open tennis championship in Melbourne, Australia, Friday, Jan. 17, 2020. (AP PhotoLee Jin-man)

And it made her the first woman in the professional era with at least one title in four decades: the 1990s, 2000s, 2010s and 2020s.

A year ago in Australia, Williams held match points in the quarterfinals against Karolina Pliskova before twisting her ankle and eventually losing.

"She's going to be, always, tough," the second-seeded Pliskova said, “no matter which ranking she is, no matter, I think, which age she is.”

Switzerland's Roger Federer serves during a practice session ahead of the Australian Open tennis championship in Melbourne, Australia, Sunday, Jan. 19, 2020. (AP PhotoLee Jin-man)

Switzerland's Roger Federer serves during a practice session ahead of the Australian Open tennis championship in Melbourne, Australia, Sunday, Jan. 19, 2020. (AP PhotoLee Jin-man)

Here are other things to know about the Australian Open, the year's first Grand Slam tournament:

AIR QUALITY

The high heat of the Australian summer is always a factor in Melbourne, but this time more attention will be paid to the air quality because of the wildfires that have been burning in the eastern parts of the country, including about 100 miles away. Smoke that reached the tournament site affected some players during qualifying last week, but has been dissipating. Rain in the forecast at the start of the main draw could help further,

Spain's Rafael Nadal makes forehand return during a practice session ahead of the Australian Open tennis championship in Melbourne, Australia, Sunday, Jan. 19, 2020. (AP PhotoDita Alangkara)

Spain's Rafael Nadal makes forehand return during a practice session ahead of the Australian Open tennis championship in Melbourne, Australia, Sunday, Jan. 19, 2020. (AP PhotoDita Alangkara)

BIG THREE

Top-ranked Rafael Nadal, defending champion Novak Djokovic and Roger Federer have won 55 of the past 66 Grand Slam titles, including 12 in a row and 14 of the most recent 16 in Australia. If Nadal, last year's runner-up, wins his second Australian Open trophy (the other came in 2009), he would match Federer's men's record of 20 Grand Slam titles. Djokovic sits third with 16.

YOUNG RUSSIANS

Serbia's Novak Djokovic gestures during a press conference ahead of the Australian Open tennis championship in Melbourne, Australia, Sunday, Jan. 19, 2020. (AP PhotoDita Alangkara)

Serbia's Novak Djokovic gestures during a press conference ahead of the Australian Open tennis championship in Melbourne, Australia, Sunday, Jan. 19, 2020. (AP PhotoDita Alangkara)

Eventually, the Big Three's grip on tennis will subside. And eventually, some younger player will assert himself. Tennis' great guessing game right now is when those things will happen — and who'll be the first of the kids to win a Grand Slam title. Right now, there is a trio of young Russians pushing their way into the conversation: No. 4 seed Daniil Medvedev, who is 23 years old; No. 16 Karen Khachanov, also 23; and No. 17 Andrey Rublev, 22. Medvedev pushed Nadal to five sets in last year's U.S. Open final; Khachanov was a 2019 French Open quarterfinalist; Rublev's trophies this month at Doha and Adelaide made him the first man since 2004 with two tour-level titles before the Australian Open.

OSAKA'S DEFENSE

Naomi Osaka's first Grand Slam title defense ended with a fourth-round loss at the U.S. Open. Now comes her second such effort and this one will come with a new coach at her side — and her fourth in the past year — Wim Fissette, who has worked with players such as Kim Clijsters and Angelique Kerber in the past. “She learns a lot from mistakes, and it's normal at her age to make some mistakes,” Fissette said about the 22-year-old Osaka. “But she is a very quick learner with everything she does. She has her eyes open and her ears open. ... From what she told me, I believe she learned a lot from that experience at the U.S. Open.”

Russia's Andrey Rublev poses with the trophy after winning the Adelaide International tennis final match in Adelaide, Saturday, Jan. 18, 2020. (AP PhotoJames Elsby)

Russia's Andrey Rublev poses with the trophy after winning the Adelaide International tennis final match in Adelaide, Saturday, Jan. 18, 2020. (AP PhotoJames Elsby)

WOZNIACKI'S EXIT

Caroline Wozniacki is playing what she says will be the final tournament of a career that includes the 2018 Australian Open title and time at No. 1 in the WTA rankings. She's 29. “I'm sure once the last ball is hit,” she said, “it's going to be a bit emotional.”

YOU SAY HELLO, I SAY GOODBYE

Japan's Naomi Osaka warms-up with her coach Wim Fissette during a practice session ahead of the Australian Open tennis championship in Melbourne, Australia, Sunday, Jan. 19, 2020. (AP PhotoAndy Wong)

Japan's Naomi Osaka warms-up with her coach Wim Fissette during a practice session ahead of the Australian Open tennis championship in Melbourne, Australia, Sunday, Jan. 19, 2020. (AP PhotoAndy Wong)

The Australian Open doubles competition will see some notable comings and goings. Bob and Mike Bryan, 41-year-old American twins who own a record 16 Grand Slam championships in men's doubles, are competing in Melbourne for the final time; they've announced 2020 is their last year on tour. And Sania Mirza, a 33-year-old from India with a total of six major titles in women's or mixed doubles, is back in Grand Slam action for the first time in two years after having a baby.

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