Coco Gauff was given a solid workout by former champion Sofia Kenin but continued her lengthy winning streak to reach the second round of the Australian Open with a 6-3 6-3 victory on Rod Laver Arena on Monday.
The third seed, who led the United States to a United Cup triumph in Sydney to kick off her season, was troubled as much by the bright sunshine and her own errors as Kenin's game in a tricky first set, which she won with an ace after 44 minutes.
Kenin, who beat Gauff on her way to the title at Melbourne Park in 2020, again blew hot and cold to keep things interesting in the second set but dropped her head after failing to break back for 4-4.
Former US Open champion Gauff pounced to break her fellow American for a fourth time in the match and secured her 10th straight singles victory when Kenin sent a wild forehand well wide of the tramlines.
"It was a tough match for me today but I'm happy with how I played. I could have served better but I could hardly see at (one) end," said the 20-year-old, who mixed 12 aces with nine double faults over the match.
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Gauff, whose best performance in Melbourne was her semifinal loss to eventual champion Aryna Sabalenka last year, will next face Britain's Jodie Burrage.
SWIATEK BATTLES PAST SINIAKOVA
Iga Swiatek battled past a gritty Katerina Siniakova in straight sets at the Australian Open on Monday to launch her quest for a sixth Grand Slam title and first at Melbourne Park.
The world No 2, who served a one-month doping suspension last year and lost her top ranking to Aryna Sabalenka, beat the 46th-ranked Czech 6-3, 6-4 on John Cain Arena.
"For sure it wasn't an easy first round. So I'm happy that I'm through," said the Pole.
She will face 49th-ranked Slovakian Rebecca Sramkova in the second round.
It wasn't all plain sailing against the doubles specialist Siniakova.
Second seed Swiatek appeared to be cruising at 4-2 and 40-0 up in the first set when Siniakova suddenly found another gear to break back.
Swiatek berated herself and came out aggressively after the changeover to break Siniakova again and serve out for the set in 38 minutes.
Swiatek edged 2-0 in front at the start of the second but again the nine-time doubles Grand Slam champion managed to get back on serve.
Another break gave Swiatek the edge once more and this time she closed out the match in 81 minutes.
"Katerina, I know her from playing doubles against her that she's not an easy opponent," admitted Swiatek.
"She was playing really well and I just needed to be more proactive. I did that in the second set, so I'm happy."
The 23-year-old Swiatek has never shone at Melbourne Park.
She has only progressed beyond the fourth round at the Australian Open in 2022, when she was upset by Danielle Collins in the semifinals.
Swiatek began her 2025 campaign with four singles wins out of five in the United Cup, her first event since it was revealed she had served a doping suspension.
Swiatek pulled out of the WTA's late-season Asian swing citing "personal matters".
Later it emerged she had been under a one-month suspension for testing positive for a banned heart medication. She denies knowingly doping.
The Polish star has fourth seed Jasmine Paolini, sixth seed Elena Rybakina and eighth seed Emma Navarro lurking in her half of the draw.
But she cannot face the world No 1 and defending champion Sabalenka until the final, should she get that far.
OSAKA, PEGULA WIN; AZARENKA OUT
Another winner was two-time Australian Open champion Naomi Osaka, who defeated France's Caroline Garcia 6-3, 3-6, 6-3.
Victoria Azarenka, the 2012 and 2013 champion, was a notable early loser as the Belarusian went down 6-2, 7-6 (7/2) to Italy's Lucia Bronzetti.
US Open finalist Jessica Pegula, the seventh-seeded American, blew away home player Maya Joint 6-3, 6-0.