It propelled her back into the world top 10 but Williams, 35, was no match for Konta, who raced to a 6-4, 6-2 victory in 79 minutes on Rod Laver Arena for one of the biggest wins of her career.
Johanna Konta caused a huge upset in the Australian Open when she dumped Venus Williams in the first round by winning 6-4, 6-2.
"I just needed that time to just recover the best of my ability and get really fit, you know, and really train and get ready for the season".
The American's troublesome knee forced her to pull out of the Hopman Cup last week and she was pictured taking treatment during a practice session in Melbourne on Saturday.
Williams, who just missed a calendar year Grand Slam last year by losing in the semifinals at the U.S. Open, plays Camila Giorgi of Italy, followed by Djokovic's match against Chung Hyeon of South Korea.
Tennis Australia chief executive and Australian Open tournament director Craig Tiley hit out at the timing of the report, and said the season's first Grand Slam was known for its integrity.
"I played two previous tournaments and didn't have the right results but I have strong belief in the way I want to play".
"So the facts are, it's a bet-on sport and will continue to be a bet-on sport, and authorities need to understand that and work closely with the betting operators because of that", Scotney said.
The report, which also alleges that one top-50 player competing in the Australian Open is suspected of "repeatedly fixing his first set", did not name the implicated players, saying it couldn't definitively prove they were involved in illegal activities.
"I'm very pleased with how I played today, how I handled the nerves and everything", Kvitova said.
She said she was thinking, "OK, I haven't played in a long time, but I have been playing for 30 years, so I try to focus on that".
Maria Sharapova, who lost to Williams in the final here past year and could meet her again in the quarterfinals, showed no signs of a left forearm injury that curtailed her preparations when she beat Nao Hibino 6-1, 6-3 in a night match. I didn't sleep well actually.
The BBC and BuzzFeed News have obtained "secret files" that reportedly contain evidence of suspected match-fixing in tennis.
An International Tennis Federation spokesman at the Australian Open says the Tennis Integrity Unit plans to issue a statement on Monday in reaction to reports over match-fixing in the sport.
Federer beat Nikoloz Basilashvili of Georgia 6-2, 6-1, 6-2 on Monday and will face Alexandr Dolgopolov in the second round of the tournament.
Roger Federer, a 17-time major victor and former leader of the player council, agreed the allegations likely weren't new but remained "super serious".
The BBC and BuzzFeed News said they had not named the players because without access to their phone, bank and computer records it was not possible to determine whether they took part in match-fixing.