The Williams sisters' contribution to tennis was also highlighted by Japan's Naomi Osaka, who reached the second round after demolishing Russia's Anastasia Pavlyuchenkova.
Here are some of the best moments from the 2019 Australian Open.
Former champion Stan Wawrinka battled past Russian fourth seed Daniil Medvedev in five sets to reach the Australian Open quarter-finals with a 6-2, 2-6, 4-6, 7-6(2), 6-2 victory. Fifth seed Dominic Thiem kept his flawless record against Gael Monfils intact with a trouble-free 6-2, 6-4, 6-4 victory on Monday to reach his maiden Australian Open quarter-final.
Garbine Muguruza stormed back into the Grand Slam big time with a 7-5, 6-3 win over Russian Anastasia Pavlyuchenkova to reach her first Australian Open semi-final. Fourth seed Simona Halep advanced to her second Australian Open semi-final with a 6-1, 6-1 demolition of Estonia's Anett Kontaveit in just 53 minutes on Rod Laver Arena.
Novak Djokovic will begin his Australian Open title defence against Frenchman Jeremy Chardy, while reigning women's champion Sofia Kenin meets wild card Maddison Inglis, following the draw for the year's first Grand Slam on Friday.
The 24-year-old was staring at defeat while down a set and a break but dug deep to prevail in two hours 24 minutes for his 200th tour match victory and his 10th ATP title.
Novak Djokovic launched his bid to stay on course for a Golden Slam with a clinical 6-2, 6-2 win over 139th-ranked Hugo Dellien of Bolivia on Saturday, as sweltering conditions in Tokyo took a toll on the players on the opening day of tennis at the Games.
Sania Mirza reached her first Grand Slam semi-final of the year with China's Shuai Peng after outclassing Timea Babos and Andrea Hlavackova in the women's doubles, at the US Open, in New York.
Zverev has not lost to Wawrinka in two previous meetings but is not taking the 2014 Melbourne Park champion lightly.
Frances Tiafoe is hopeful to build on his own stature in the game as he prepares for an Australian Open quarter-final clash with Rafael Nadal on Tuesday.
We bring you best images from week one of the 2019 Australian Open Championships at Melbourne Park
Andrey Rublev and Alexander Zverev clinched the Laver Cup for Team Europe with a 6-2, 6-7(4), 10-3 win over Team World's Reilly Opelka and Denis Shapovalov on Sunday in Boston.
Hewitt defers Hall of Fame induction due to travel restrictions
India's veteran Leander Paes and his Swiss partner Martina Hingis stayed on course for their third Grand Slam of the year after advancing to the mixed doubles final at the US Open, in New York, on Wednesday night.
Serena Williams battered Anastasia Pavlyuchenkova 6-4, 6-4 in the quarter-finals at Wimbledon on Tuesday, seizing on moments of weakness from the Russian to ram home her advantage.
A summary of sports events and sports persons, who made news on Sunday
Millman, ranked 80 places above world number 14 Pouille, needed 73 minutes to clinch a 6-3, 6-4 victory and the best win of his career by ranking position.
A look at the records of Garbine Muguruza and Sofia Kenin ahead of their Australian Open final on Saturday.
Maria Sharapova has pulled out of Russia's Fed Cup semi-final against Germany in Sochi this weekend with a leg injury, the Russian Tennis Federation said on Tuesday.
Jana Novotna took Barbora Krejcikova under her wing in 2014 and while the youngster "never tried to imitate" her, the 2018 French Open and Wimbledon doubles champion drew inspiration from her mentor.
She remained philosophical in defeat, however, saying that her expectations coming into the tournament had not been high.
Fifth seed Ana Ivanovic was knocked out of the Australian Open first round on Monday when she was upset by doubles specialist Lucie Hradecka 1-6, 6-3, 6-2.
Coming off a fruitful year which yielded two grand slam titles, world number two Federer looked fit and sharp while other members of tennis's 'Big Four' are grappling with injury issues.
Images from Day 8 of the 2021 French Open at Roland Garros in Paris on Sunday
Grand Slam champions Daniil Medvedev from Russia and Belarusian Victoria Azarenka will not be able to participate in the June 27-July 10 tournament.
World number two Rafael Nadal confirmed on Tuesday that he will not defend his US Open crown this year at Flushing Meadows as organisers released the singles entry list for the Grand Slam. Spain's Nadal had said in June that he had reservations about travelling to the U.S. amid the COVID-19 pandemic and he joins women's world number one Australian Ash Barty in skipping the tournament due to COVID-19 concerns.
Serena Williams showed glimpses of what lies in store for rivals this season
Nadal meets the 'new Nick' Kyrgios in fourth-round blockbuster
He leads the men's seedings ahead of defending champ Roger Federer, with Bulgarian Grigor Dimitrov seeded third.
Former world number one Victoria Azarenka criticised French Open organisers on Sunday for scheduling men's matches in all but one of the night slots so far this year.
Novak Djokovic kept his juggernaut rolling at the China Open by improving to 26-0 with a 6-2, 6-1 win over local hope Zhang Ze on Thursday.
India's Sania Mirza is standing on the cusp of history as she is now one win away from becoming World No 1.
Venus Williams was not prepared to even countenance the suggestion she could potentially meet younger sister Serena in the Australian Open final after she advanced to the quarter-finals with a 6-3, 7-5 victory over Mona Barthel on Sunday.
The 23-year-old Wimbledon champion, who climbed to the top of the WTA rankings on Monday, hardly broke sweat against the Frenchwoman, ranked 20th in the world, on her way to victory in an hour and 20 minutes.
Organisers hope the anxious buildup will be forgotten when the action begins.
Images from Day 4 of the Australian Open in Melbourne on Thursday.
Russia's Elena Vesnina ousted German second seed Angelique Kerber 6-3, 6-3 to reach the quarter-finals of the BNP Paribas Open at Indian Wells, California on Tuesday.
Svetlana Kuznetsova opened the defence of her Sydney International title with a comfortable 6-1, 6-4 victory over Irina-Camelia Begu on Sunday as the Australian Open warm-up event suffered a pair of big-name withdrawals.
Venus Williams moved within two wins of a possible sisterly showdown with Serena in the semi-finals of the US Open by beating German 26th seed Laura Siegemund to reach the fourth round on Saturday.
Roger Federer took 55 minutes to dispel all injury doubts with a 6-2, 6-1 routing of unheralded German Tobias Kamke in the second round of the Brisbane International on Thursday. Media speculations swirled around the fitness of the world number three less than two weeks before he launches his bid for a fifth Australian Open title and the Swiss maestro dismissed them by dropping only three games in a lop-sided contest. "I'm going to do my best to stay injury free and give myself a chance to win another grand slam," Federer said after setting up a quarter-final against Grigor Dimitrov.