Serena in charge as Li gets workout

Melbourne: Serena Williams kept her cool in the scorching Melbourne heat to make the Australian Open third round today, where she was joined by hard-working fourth seed Li Na.

The imposing world number one and top seed stormed through her match in oven-like conditions on Rod Laver Arena, crushing Serbia's Vesna Dolonc 6-1, 6-2 in just 63 minutes.

Williams is the firm favourite ahead of defending champion Victoria Azarenka to win a sixth Melbourne crown, and the American reinforced her credentials with a customary towering performance.

Now 32, she denied being favourite added any pressure, having been in similar positions many times before.

"Well, to me there is always pressure. It always seems like I'm one of the favourites to win," said Williams, who next plays either the experienced Slovak Daniela Hantuchova or Czech Karolina Pliskova.

"But for me, I look at it as kind of exciting that I have an opportunity to go all the way.

"But with that being said, I have so many matches I have to win in order to do well and in order to lift the trophy. It's such a long way."

The victory was yet another landmark for the American veteran, who is gunning to match the achievement of Chris Evert and Martina Navratilova in winning her 18th Grand Slam title.

In beating Dolonc, she drew level with Margaret Court's record in winning her 60th match at the Australian Open.

Williams has now played 68 times at Melbourne Park, with only Lindsay Davenport on 69 having graced the Australian courts more in the Open era.

China's Li is another serious title contender, having twice made the Melbourne final including last year when she lost to Azarenka in heartbreaking fashion after twice going down with an ankle injury.

While Williams was out of the 40 Celsius (104 Fahrenheit) heat in barely an hour, Li was forced to stay in the sun longer after a second-set challenge from Swiss qualifier Belinda Bencic.

The first set was easy but the second proved to be a serious workout for the Chinese star, who is searching for her second Grand Slam title after the French Open in 2011.

She admitted she was not at her best in the 6-0, 7-6 (7/5) victory.

"I cannot say I played 100 percent," Li said. "Of course I cannot play 100 percent every day, but (I played) at least 60, 65 percent."

Defeat was painful for Bencic, but at just 16 the 2013 Wimbledon and French Open junior champion said the tournament had been a valuable experience.

"It's great that I had this experience at 16, so maybe later or the next match I can show what I learned from this experience so I will not be so nervous and I will not miss chances," she said.

Li next faces 26th seeded Lucie Safarova, who came from a set down to beat fellow Czech Lucie Hradecka 6-7 (4/7), 6-3, 6-0.

Other players through included Russian 22nd seed Ekaterina Makarova, Italian Flavia Pennetta and Germany's Mona Barthel, who swept past Thai hope Luksika Kumkhum.

Azarenka, gunning for her third straight Australian Open title, and third seed Maria Sharapova play their second round matches on Thursday.