Melbourne - Serena Williams has been handed a challenging draw in her quest for a record-equalling 24th Grand Slam title at the Australian Open, starting with Germany's Tatjana Maria in the first round.
The American, seeded 16, is gunning to match Margaret Court's record of singles majors and claim an eighth Australian Open crown.
But Williams is in a tough half of the draw and could meet world number one Simona Halep in round four, and if she gets through that Karolina Pliskova in the last eight.
Before those potential ties, either Chinese wildcard Peng Shui or Canadian Eugenie Bouchard would await Williams in the second round.
Halep, who enters the tournament having played just one game in four months after a back injury, was handed a chance to avenge Estonia's Kaia Kanepi, who beat her in the first round of the US Open in August.
If she comes through that dangerous opening showdown, she could meet Venus Williams in round three.
Defending champion and third seed Caroline Wozniacki starts against Alison Van Uytvanck of Belgium and could meet 2008 champion Maria Sharapova in round three.
"Coming back as defending champion, it's something I always dreamed of. I feel at home here. These courts are suited for me. I'm enjoying every minute," said the Dane at Thursday's draw, while paying tribute to Williams.
"Serena is the greatest player to have played the game. Her experiences have been a learning experience for me. It's be fun though as well. She has a baby now! It's amazing being back on tour so soon."
The 2016 winner Angelique Kerber, seeded two, begins her draw against Slovenia's Polona Hercog and could meet fifth seed Wozniacki in the semis.
Japan's Naomi Osaka, the US Open champion, kicks off her tournament against Poland's Magda Linette and is in line to meet Australia's Daria Gavrilova round two.
The draw made on Thursday for the Australian Open women's singles in Melbourne next week (x denotes seeding):
Simona Halep (ROU x1) v Kaia Kanepi (EST)
Sofia Kenin (USA) v Qualifier
Alize Cornet (FRA) v Lara Arruabarrena (ESP)
Venus Williams (USA) v Mihaela Buzarnescu (ROU x25)
Carla Suarez Navarro (ESP x23) v Clara Burel (FRA)
Samantha Stosur (AUS) v Dayana Yastremska (UKR)
Eugenie Bouchard (CAN) v Peng Shuai (CHN)
Tatjana Maria (GER) v Serena Williams (USA x16)
Daria Kasatkina (RUS x10) v Timea Bacsinszky (SUI)
Qualifier v Qualifier
Johanna Konta (GBR) v Ajla Tomljanovic (AUS)
Zheng Saisai (CHN) v Garbine Muguruza (ESP x18)
Camila Giorgi (ITA x27) v Dalila Jakupovic (SLO)
Qualifier v Ann Bogdan (ROU)
Madison Brengle (USA) v Qualifier
Qualifier v Karolina Pliskova (CZE x7)
Naomi Osaka (JPN x4) v Magda Linette (POL)
Tamara Zidansek (SLO) v Daria Gavrilova (AUS)
Laura Siegemund (GER) v Victoria Azarenka (BLR)
Stefanie Voegele (SUI) v Hsieh Su-Wei (TPE x28)
Qiang Wang (CHN x21) v Finoa Ferro (FRA)
Zarina Diyas (KAZ) v Aleksandra Krunic (SRB)
Qualifier v Whitney Osuigwe (USA)
Mona Barthel (GER) v Anastasija Sevastova (LAT x13)
Elise Merten (BEL x12) v Anna Karolina Schmeidlova (SLO)
Qualifier v Margarita Gasparyan (RUS)
Pauline Parmentier (FRA) v Anatasia Potapova (RUS)
Destanee Aiava (AUS) v Madison Keys (USA x17)
Dominika Cibulkova (SLO x26) v Zhang Shuai (CHN)
Karolina Pliskova (CZE x7) Anna Blinkova (RUS)
Viktoria Kuzmova (SLO) v Kateryna Kozlova (UKR)
Qualifier v Elina Svitolina (UKR x6)
Petra Kvitova (CZE x8) v Magdalena Rybarikova (SLO)
Irina-Camelia Begu (ROM) v Anna Petkovic (GER)
Belinda Bencic (SUI) Katerina Siniakova (CZE)
Yulia Putinseva (KAZ) v Barbora Strycova (CZE x32)
Monica Niculescu (ROM) v Amanda Anisimova (USA)
Katie Boulter (GBR) v Ekaterina Makarova (RUS)
Qualifier v Aryna Sabalenka (BLR x11)
Ashleigh Barty (AUS x15) v Luksika Kumkhum (THA)
Ellen Perez (AUS) v Wang Yafan (CHN)
Qualifier v Priscilla Hon (AUS)
Maria Sakkari (GRE) v Jelena Ostapenko (LAT x22)
Maria Sharapova (RUS x30) v Qualifier
Sorana Cirstea (ROM) v Rebecca Peterson (SWE)
Vera Lapko (BLR) v Johanna Larsson (SWE)
Alison Van Uytvanck (BEL) v Caroline Wozniacki (DEN x3)
Sloane Stephens (USA x5) v Taylor Townsend (USA)
Ons Jabeur (TUN) v Timea Babos (HUN)
Marketa Vondrousova (CZE) v Evgeniya Rodina (RUS)
Heather Watson (GBR) v Petra Martic (CRO x31)
Anett Kontaveit (EST x20) v Sara Sorribes Tormo (ESP)
Kirsten Flipkens (BEL) v Aliaksandra Sasnovich (BLR)
Monica Puig (PUR) v Anastasia Pavlyuchenkova (RUS)
Alison Riske (USA) v Kiki Bertens (NED x9)
Julia Goerges (GER X14) v Danielle Collins (USA)
Qualifier v Sachia Vickery (USA)
Bethanie Nattek-Sands (USA) v Zoe Hives (AUS)
Qualifier v Caroline Garcia (FRA x19)
Donna Vekic (CRO x29) v Kristina Mladenovic (FRA)
Qualifier v Kimberly Birrel (AUS)
Qualifier v Bernarda Pera (USA)
Polona Hercog (SLO) v Angelique Kerber (GER x2)