China's Zheng Qinwen celebrates after victory against Romania's Anca Todoni during their women's singles match on day one of the Australian Open in Melbourne on Sunday.

MELBOURNE — Olympic champion Zheng Qinwen overcame a sluggish start to blast into the Australian Open second round on Sunday as storms caused havoc ahead of Aryna Sabalenka beginning her quest for a historic third consecutive crown.

Fifth seed Zheng, last year's losing finalist, had the honor of playing the first point on center court at the opening Grand Slam of the season against Romania's 110th-ranked Anca Todoni

She came through unscathed 7-6(7/3), 6-1 on Rod Laver Arena but was clearly rusty after opting not to play a warm-up event.

Zheng had three set points on-serve at 5-3 in the first set, but allowed Todoni to come roaring back before closing her down in the tiebreak and then racing through the second set.

"The first match is always not easy," she said. "Just happy to get through the match, the tiebreak and find my rhythm."

The 22-year-old enjoyed a breakthrough 2024 with her Australian Open exploits helping spur her to Olympic gold — beating Iga Swiatek on the way — and two WTA titles.

While Zheng was able to play, the action on the outside courts at Melbourne Park was halted barely an hour after it started when storms rolled in that turned the sky black.

Thunder and lightning saw players and fans rushing for cover, with heavy rain lashing Melbourne Park in a headache for organizers with a match backlog looming.

Only the three main stadiums — Rod Laver Arena, Margaret Court Arena and John Cain Arena — have roofs.

Mirra Andreeva was the first player through to the second round, with the 14th-seeded Russian easing past the Czech Republic's Marie Bouzkova 6-3, 6-3 on John Cain Arena.

The 17-year-old made a run in Melbourne last year to the fourth round with her next opponent being either Poland's Magda Linette or Japan's Moyika Uchijima.

"Honestly it was a bit hard for me when they started closing the roof (mid-match)," said Andreeva, who is coached by former Wimbledon champion Conchita Martinez.

"I'm very happy today that I played in a stadium with a roof."

Later on Sunday, a battling Sabalenka survived an early wobble to beat Sloane Stephens 6-3, 6-2 as the world No 1 began her bid for a historic hat-trick at the Australian Open.

Sinner's title defense

The first round of the Australian Open continues on Monday at Melbourne Park where top seed and defending champion Jannik Sinner seeks a third Grand Slam title while Novak Djokovic begins his quest for a record-extending 25th major.

World No 1 Sinner is playing under the cloud of a potential two-year ban due to his doping case while 37-year-old Djokovic, a 10-time champion in Melbourne, returns to his favorite hunting ground as the seventh seed.

Carlos Alcaraz and Iga Swiatek are also in action while four Australians, including Nick Kyrgios, will get their chance to shine on the showcourts.

Kyrgios returns to Grand Slam action for the first time in two years when the Australian takes on Briton Jacob Fearnley.

Kyrgios has been sidelined due to knee, foot and wrist problems and he returns to his home Slam as an unranked player, still struggling with an abdominal strain and "niggles" that forced him to pull out of an exhibition event.

The 29-year-old spent some time in the broadcast booth during his break from the game but he is confident tennis has not left him behind.

"People are always going to say, 'Be realistic, you're not going to be the same'. I unfortunately don't have that mindset. I always have the utmost confidence in my ability," said Kyrgios, whose best result in Melbourne was a quarterfinal run in 2015.

"If I'm playing my style of tennis, my unpredictability, I have a chance against anyone."

The Australian Open marks Fearnley's second main draw appearance at a Grand Slam but he made his mark at his first at Wimbledon last year, winning his opening round match and then taking a set off Djokovic on center court.