MELBOURNE (AFP) - Serena Williams and Li Na led the march into the Australian Open second round on Monday but former great Venus Williams and sixth seed Petra Kvitova crashed out in the Melbourne heat.
World No.1 Serena crushed local hope Ashleigh Barty 6-2, 6-1 in clinical fashion to reinforce her position as title favourite as she hunts for an 18th Grand Slam singles tennis crown to match Chris Evert and Martina Navratilova.
"I want to do well here, I would love to have a win, but there are so many good opponents," Williams said, playing down her chances.
"It doesn't matter whether I win or lose, as long as I have fun. As long as I'm able to stay relaxed, I'll be okay."
Victory over Barty, 17, set up a second-round clash with Serbia's Vesna Dolonc, with Williams on track to meet charismatic fourth seed Li in the semi-finals.
The Chinese demolished junior champion Ana Konjuh 6-2, 6-0 as she set about ending her tournament jinx.
Li has made the final at Melbourne Park twice before, leading both times before being overcome by Kim Clijsters in 2011 and Victoria Azarenka last year, and she is determined to go one better this time round.
"I always love coming to Melbourne." she said. "I'm feeling good and feeling healthy."
Her easy win set up a second-round clash with another qualifier in Swiss Belinda Bencic, who beat 43-year-old Japanese veteran Kimiko Date-Krumm, 27 years her senior.
Defending champion Azarenka plays on Tuesday.
Also through was Germany's ninth seed Angelique Kerber, who had a second-set wipeout before bouncing back to overcome Australian Jarmila Gajosova 6-3, 0-6, 6-2.
Former world No.1 Ana Ivanovic and local hope Samantha Stosur also safely booked their second round berths.
But 2011 Wimbledon champion Kvitova slumped to a shock 6-2, 1-6, 6-4 defeat by little-known Thai Luksika Kumkhum, leaving her bitterly disappointed.
"I think that probably I wanted it too much, and then everything just fell down," said the Czech.
Italy's seventh seed Sara Errani went the same way, limping out to Germany's Julia Goerges.
It was also curtains for seven-time Grand Slam champion Venus Williams, who fell in a marathon clash against Russian 22nd seed Ekaterina Makarova.
Williams was unseeded despite playing 11 events last year and making three semi-finals, and she looked on course for victory after winning the first set.
But a series of unforced errors and failure to convert crucial break points cost her dearly and she was sent packing 2-6, 6-4, 6-4 after a nearly two-and-half-hour epic.
"Obviously losing any match is never any fun, especially in a major. So definitely I would have wanted a different result," she said.
"I think my error count was a little high. I haven't looked at the stats yet, so I don't know what the errors were or the first-serve percentage was. I have to look at that and just kind of evaluate the match."
Williams has not won a Grand Slam since Wimbledon in 2008 and is without a title since Luxembourg in October 2012.
Her defeat was in stark contrast to sister Serena, who had never lost in the opening round of the Australian Open in 13 previous appearances, highlighting the massive odds facing wildcard Barty.
The Australian won her opening service game to a huge cheer from the crowd but Williams was just finding her stride, easily holding the next and then breaking the local girl to signal her intent.
Williams, in a figure-hugging pink and black outfit, then went through the gears, smashing winners on the forehand and backhand to wrap up the opening set in 31 minutes.
She began the second where she left off, breaking Barty immediately and there was no coming back for the teenager.