Melbourne (AFP) - Nick Kyrgios pulled out injured as the Australian Open lost another big name on Monday, while Coco Gauff and Jessica Pegula fired early warning shots with convincing wins.
The first Grand Slam of the year lost several stars in the build-up and unpredictable home hope Kyrgios became the latest casualty, his tournament over on day one before he hit a ball.
"I'm devastated, obviously," the Wimbledon finalist told a hastily arranged press conference, having suffered a knee injury.
Injured men's world number one Carlos Alcaraz and two-time Melbourne champion Naomi Osaka -- who is expecting her first child -- are among the other high-profile players missing.
The sudden absence of talented but temperamental Kyrgios further opens the door for nine-time Australian Open champion Novak Djokovic and title holder Rafael Nadal.
Gauff v Raducanu
In the opening action, in-form third seed Pegula blitzed 161st-ranked Romanian Jaqueline Cristian on Margaret Court Arena 6-0, 6-1 in a 59-minute romp to signal her intent.
Also on day one, fellow American Gauff was equally explosive in racing into the second round with a 6-1, 6-4 thumping of Czech Katerina Siniakova on the neighbouring Rod Laver Arena.
Gauff headed into Melbourne on a high after winning her third WTA title at the Auckland Classic, while Pegula was boosted by upsetting world number one Iga Swiatek at the United Cup.
The 18-year-old Gauff now faces a mouth-watering second-round encounter against former US Open champion Emma Raducanu, who beat Tamara Korpatsch 6-3, 6-2, barely 10 days after the Briton exited the Auckland event in tears with an ankle injury.
It will be a first meeting ever between teenager Gauff and the 20-year-old Raducanu.
"I'm really looking forward to this match," Raducanu said.
"I'm very up for it.Coco has obviously done a lot of great things and she's playing well.
"I think we're both good, young players, we're both coming through -- part of the next generation of tennis really -- it's going to be a great match."
Also safely through was another American, Danielle Collins, last year's beaten finalist in Melbourne.She beat Anna Kalinskaya 7-5, 5-7, 6-4.
Greek sixth seed Maria Sakkari also won.
But two seeds fell at the first hurdle, 25th-seeded Czech Marie Bouzkova and American 28th seed Amanda Anisimova.
Top seed Swiatek gets her campaign for a first Melbourne Park title under way later Monday against Germany's Jule Niemeier.
Nadal's tough test
Spanish great Nadal is in action on Monday with a tricky first-round encounter against Britain's fast-rising Jack Draper.
Top seed Nadal, who boasts a record 22 major titles, has been struggling for form, and admitted Draper was dangerous.
"Probably one of the toughest first rounds possible...young, powerful, growing very, very fast in the rankings, playing well," said Nadal of Draper, aged 21, the world number 38.
Daniil Medvedev, Australian Open runner-up for the past two years, faces 56th-ranked American Marcos Giron.
Also in action on Monday are men's third seed Stefanos Tsitsipas, who plays Frenchman Quentin Halys.
Djokovic, who was detained and deported ahead of last year's tournament after refusing to get vaccinated for Covid-19, begins his campaign for a record-extending 10th Australian Open title on Tuesday.
Teenager Shang Juncheng created a slice of history Monday by becoming the first men's Chinese player to win an Australian Open main-draw singles match.
The gifted 17-year-old, a qualifier, battled past Germany's Oscar Otte in nearly three hours to progress.
