Top seed Roger Federer beat Germany's Bjorn Phau 7-5, 6-0, 6-4 to open his Australian Open defence.
An Australian Open official said Williams had withdrawn from the first Grand Slam of 2007 because of a left wrist injury.
Images from Day 1 of the Australian Open, in Melbourne, on Monday.
Eugenie Bouchard will spend Monday 'cramming' for one of the toughest exams of her fledgling career when she faces second seed Maria Sharapova in the Australian Open quarter-finals.
For someone who is the defending champion at Melbourne Park, Stanislas Wawrinka is remarkably upbeat about the lack of focus falling upon him.
Images from Sunday's action at the Australian Open in Melbourne.
Players will allowed to question more line calls at the year's first Grand Slam.
Last week, Court wrote an open letter to Qantas Airlines opposing their support of same-sex marriage and her beliefs were condemned by several current and former players, including Australia's Samantha Stosur, Nick Kyrgios and Jaimee Fourlis.
Canada's Denis Shapovalov said he would flat out refuse to go on court if forced to compete in poor air quality and believed other leading players at the tournament will similarly decline to risk their health.
Pouille had devised a strategy with his coach Amelie Mauresmo to topple the top seed in the semi-final at a floodlit Rod Laver Arena.
Melbourne final feels 'bit unreal' for Japan's Osaka
Novak Djokovic held off a Roger Federer fightback as he reached the final of the Australian Open for the fifth time in six years. Poland's Agnieszka Radwanska was taken apart 6-0 6-4 by the reigning women's champion Serena Williams.
"She played some incredible points on match point, she reminded me a bit of myself," said Williams after the match.
Martina Hingis played spoilsport at the Australian Open on Monday by denying China another entry into the record books.
Fourth seed Kim Clijsters overcame a late wobble to beat Slovakian Daniela Hantuchova 6-1 7-5 on Monday and set up a mouth-watering Australian Open quarter-final against Martina Hingis.
Andy Roddick and Serena Williams scored contrasting wins to enter the Australian Open quarterfinals.
China's Na Li kept the Asian interest alive as she beat ninth seed Dinara Safina 6-2, 6-2.
He now faces Serbian 14th seed Novak Djokovic for a place in the Australian Open quarter-finals.
Mauresmo stayed on course to defend her Australian Open title with a 6-3, 6-1 win over Czech Eva Birnerova in the third round on Friday.
Australian Open organisers are on high alert amid fears ethnic clashes between Serbs and Croats that marred the opening day of the Grand Slam could erupt again.
The world number two believes he is ready to claim his maiden Australian Open crown.
The world number one eased past Russia's Marat Safin at the Kooyong Classic invitational event on Thursday.
The world number one, who missed the Australian Open last year, posted a 6-2, 6-2 win against Japan's Aiko Nakamura.
Newly crowned Australian Open champion NOvak Djokovic was not short of energy as he overpowered Andy Murray to claim his sixth Australian Open title.
Davenport, who was beaten in last year's final by Serena Williams, remains on course for a quarter-final meeting with 10th seed Venus Williams or eighth seed Justine Henin-Hardenne of Belgium.
Australian Open champion Marat Safin withdrew from the Hopman Cup in Perth due to a long-standing knee injury
Factbox on Serbia's Novak Djokovic who won his sixth Australian Open men's singles title on Sunday.
Angelique Kerber's recent revival faces its toughest test in the shape of Maria Sharapova when the only two former Australian Open champions in the women's draw clash in round three on Saturday. A cool front broke the grip