The American, 35, won 6-4 6-3 in 79 minutes against the 19-year-old in scorching conditions in Melbourne.

The world number two, who is chasing a record 23rd singles Grand Slam title, said she "has nothing to lose".

"Every match I'm playing for fun. I get to travel the world and do what I do best - play tennis," she added.

Williams lost the Australian Open final last year to Angelique Kerber but won Wimbledon to equal Steffi Graf's Open era mark of 22 Grand Slam singles titles.

She has barely played since the US Open last September because of injury, and lost in the second round of this month's Auckland Classic, but eased doubts about her form and fitness with a typically powerful performance in temperatures of around 35C.

Safarova saves nine match points

Williams will face Lucie Safarova in the second round after the 29-year-old Czech saved nine match points before beating Belgium's Yanina Wickmayer 3-6 7-6 (9-7) 6-1.

Safarova saved five match points on her own serve in the second set and another four in the tie-break.

"It's not fun," said a stunned Wickmayer. "I think she served very well on certain points and other points I didn't go for enough.

"But it's normal when you have match point and you want to play it a little bit safe. Then after, you realise it's not the best option."

Best of the rest

Fifth seed Karolina Pliskova, who beat Williams in last year's US Open semi-finals, went through thanks to a 6-2 6-0 victory over Spain's Sara Sorribes Tormo.

"Even when you're not playing your best, somehow you have to win," said the 24-year-old.

"I know I can be dangerous deep in the tournament, quarters and semis, and when there are big players I can beat them."

(BBС)