Melbourne - Roger Federer and Novak Djokovic are each aiming for a record seventh men's Australian Open title and the draw has ensured they can't play each other at Melbourne Park until the final.
Serena Williams already has seven Aussie titles, and is a strong contender to add another after skipping her title defence in 2018 while she was on leave after having a baby.
Now seeded 16th, Williams was drawn into the same section Thursday as No 1-ranked Simona Halep, the runner-up last year. The pair could meet in the fourth round.
No 1-ranked Djokovic starts at the top of the draw and will open against a qualifier.
He has the potential of a second round meeting against wildcard entry Jo-Wilfried Tsonga. He defeated Tsonga in the 2008 Australian final.
Djokovic also has a potential quarter-final against No 8-seeded Kei Nishikori.
No 4 Alexander Zverev is in the same half and looms in the semi-finals if both players advance that far.
Defending champion Federer is in the bottom half of the draw with No 2-ranked Rafael Nadal.
Aiming for a third consecutive Australian championship, a 21st Grand Slam crown and a 100th career singles title, Federer will open against Denis Istomin.
And with No 6 Marin Cilic in the same quarter, there's potential for a rematch of the 2018 final a few rounds early.
That's not in Federer's focus right now.
"The moment you find out the draw, that's when you shift your focus to the first round and only the first round - not going for your seventh (title) or anything like that," said Federer, who was heading to the practice courts immediately after attending the tournament draw.
"You try to really simplify it rather than look too far ahead. To win has to be the goal, but I try not to put too much pressure on it."
Cilic has Andy Murray, who is coming back from a long-term hip injury, in his section. Murray opens against No 22-seeded Roberto Bautista Agut.
Murray won just two games in an incomplete practice match with Djokovic at Melbourne Park, showing signs he's still not fully fit after spending most of the last 18 months off the tour.
Murray played at the season-opening Brisbane International last week, where he won his first-round match against James Duckworth but lost in straight sets to Daniil Medvedev in the second, limping between points and admitting he's still dealing with his troublesome right hip.
One of the most intriguing men's first round matches features 2016 Wimbledon finalist Milos Raonic against mercurial Australian Nick Kyrgios, who is unseeded after his ranking slid from 13 into the 50s, but has tour-level wins over Federer, Nadal and Djokovic to his credit.
Williams will face Tatjana Maria in the first round, and could meet either Genie Bouchard or Peng Shuai in the second round. Halep has a tough opening encounter against Kaia Kanepi and a possible third rounder against Venus Williams.
Third-seeded Caroline Wozniacki, who won her first Grand Slam title here last year after a tough final against Halep, is in the same section as Maria Sharapova and has Petra Kvitova at the top of her quarter.
Second-seeded Angelique Kerber is in the same half as Wozniacki and has 2017 US Open champion Sloane Stephens in her quarter.
The draw made on Thursday for the Australian Open men's singles in Melbourne next week (x denotes seeding):
Novak Djokovic (SRB x1) v Qualifier
Jo-Wilfried Tsonga (FRA) v Martin Klizan (SVK)
Taro Daniel (JPN) v Qualifier
Pablo Andujar (ESP) v Denis Shapovalov (CAN x25)
David Goffin (BEL x21) v Christian Garin (CHI)
Marcel Granollers (ESP) v Marius Copil (ROU)
Jiri Vesely (CZE) v Ryan Harrison (USA)
Qualifier v Daniil Medvedev (RUS x15)
Fabio Fognini (ITA x12) v Jaume Munar (ESP)
Nicolas Jarry (CHI) v Leonardo Mayer (ARG)
Ilya Ivashka (BLR) v Malek Jaziri (TUN)
Qualifier v Pablo Carreno Busta (ESP x23)
Philipp Kohlschreiber (GER x32) v Zhe Li (CHN)
Guido Pella (ARG) v Joao Sousa (POR)
Ivo Karlovic (CRO) v Hubert Hurkacz (POL)
Qualifier v Kei Nishikori (JPN x8)
Alexander Zverev (GER x4) v Aljaz Bedene (SLO)
Jeremy Chardy (FRA) v Ugo Humbert (FRA)
Alex Bolt (AUS) v Jack Sock (USA)
Qualifier v Gilles Simon (FRA x29)
Chung Hyeon (KOR x24) v Bradley Klahn (USA)
Sam Querrey (USA) v Pierre-Hugues Herbert (FRA)
Stan Wawrinka (SWI) v Ernests Gulbis (LAT)
Nick Kyrgios (AUS) v Milos Raonic (CAN x16)
Borna Coric (CRO x11) v Steve Darcis (BEL)
Albert Ramos-Vinolas (ERP) v Marton Fucsovics (HUN)
Laslo Djere (SRB) v Evgeny Donskoy (RUS)
Filio Krajinovic (SRB) v Marco Cecchinato (ITA x17)
Lucas Pouille (FRA x28) v Mikhail Kukushkin (KAZ)
Maximilian Marterer (GER) v Qualifier
Alexi Popyrin (AUS) v Mischa Zverev (GER)
Benoit Paire (FRA) v Dominic Thiem (AUT x7)
Marin Cilic (CRO x6) v Bernard Tomic (AUS)
Andrey Rublev (RUS) v Mackenzie McDonald (USA)
Michael Mmoh (USA) v Radu Albot (MDA)
Qualifier v Fernando Verdasco (ESP x26)
Roberto Bautista Agut (ESP x22) v Andy Murray (GBR)
Federico Delbonis (ARG) v John Millman (AUS)
Yoshihito Nishioka (JPN) v Tennys Sandgren (USA)
Peter Gojowczyk (GER) v Karen Khachanov (RUS x10)
Stefanos Tsitsipas (GRE x14) v Matteo Berrettini (ITA)
Qualifier v Roberto Garballes Baena (ESP)
Qualifier v Guido Andreozzi (ARG)
Qualifier v Nikoloz Basilashvili (GEO x19)
Gael Monfils (FRA x30) v Damir Dzumhur (BIH)
Cameron Norrie (GBR) v Taylor Fritz (USA)
Qualifier v Qualifier
Denis Istomin (UZB) v Roger Federer (SWI x3)
Kevin Anderson (RSA x5) v Adrian Mannarino (FRA)
Frances Tiafoe (USA) v Qualifier
Feliciano Lopez (ESP) v Jordan Thompson (AUS)
Andreas Seppi (ITA) v Steve Johnson (USA x31)
Grigor Dimitrov (BUL x20) v Janko Tipsarevic (SRB)
Pablo Cuevas (URU) v Dusan Lajovic (SRB)
Jason Kubler (AUS) v Thomas Fabbiano (ITA)
Reilly Opelka (USA) v John Isner (USA x9)
Kyle Edmund (GBR x13) v Tomas Berdych (CZE)
Guillermo Garcia-Lopez (ESP) v Robin Haase (NED)
Marc Polmans (AUS) v Denis Kudla (USA)
Qualifier v Diego Schwartzman (ARG x 18)
Alex de Minaur (AUS x27) v Pedro Sousa (POR)
Mirza Basic (BIH) v Qualifier
Matthew Ebden (AUS) v Jan-Lennard Struff (GER)
James Duckworth (AUS) v Rafael Nadal (ESP x2)