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Novak Djokovic was having an easy time of it in his first-round match at the Australian Open, so he decided to experiment by coming to the net.

Like pretty much everything he does on the tennis court these days, it was an unqualified success. He easily beat Paolo Lorenzi 6-2, 6-0, 6-0 Tuesday to advance to the second round, as did five-time Australian Open champion Serena Williams in the last match of the night at Rod Laver Arena.

Djokovic is attempting to join Rod Laver, Pete Sampras, Roger Federer and Rafael Nadal in winning three straight Grand Slam singles titles.

"When you're 3- , 4-love up, why not try some other things, something that is not characteristic for your game," said Djokovic, who usually doesn't stray too far from the baseline. "But I am definitely working on my net game, approaching the short balls as much as I can, and take my chances."

He took them well, winning 21 of 26 points he attempted at the net.

Williams started her quest for a sixth Australian title in a match that finished nearly an hour into Wednesday morning. Appearing to have recovered from a left ankle injury that forced her out of the Brisbane International two weeks ago, Williams moved well around the court as she beat Tamira Paszek 6-3, 6-2.

Williams broke Paszek in the fifth game of the second set, then blasted four aces past the Austrian player in the next game for a 4-2 lead. She set up match point with an ace, then used a service winner to clinch it in 79 minutes.

"I'm definitely a night owl, I can stay up all night," Williams said of the late finish.

In an afternoon match on the same court, U.S. Open women's champion and Australian hope Sam Stosur was beaten by Sorana Cirstea 7-6 (2), 6-3. The Romanian later told the crowd that "probably the whole country hates me now."

Stosur's first-round loss mirrors that of Petra Kvitova, who went out in the first round of last year's U.S. Open after winning Wimbledon.

"I'm not sure if it's one of my biggest matches, but it feels like that now," said Cirstea, who had lost both her previous matches against Stosur.

Stosur saved three match points while serving, but finally lost it when her looping forehand drifted over the baseline. No Australian has won the national title since Chris O'Neil in 1978.

"Certainly not the way that I wanted, not just this tournament, but the whole summer," to play out, Stosur said. "There's not any other word for it but a total disappointment."

Second-ranked Kvitova and No. 4 Maria Sharapova advanced. After surrendering her opening service game with a double-fault, Kvitova won 12 consecutive games in a 6-2, 6-0 win over Russia's Vera Dushevina.

Sharapova, a former Australian Open and Wimbledon champion, won the first eight games of a 6-0, 6-1 win over Gisela Dulko of Argentina in her first match since returning from a left ankle injury.

The 2008 champion needed just 58 minutes for the win and the only game she lost was on her own serve.

Other women advancing included No. 7 Vera Zvonareva, No. 9 Marion Bartoli and former French Open champion Ana Ivanovic.

No. 14 Sabine Lisicki, No. 17 Dominika Cibulkova, No. 27 Maria Kirilenko, Canada's Aleksandra Wozniak, Shahar Peer of Israel and 2000 Wimbledon semifinalist Jelena Dokic also advanced.

Joining Djokovic in the second round of the men's draw is the player he beat last year in the final here, fourth-seeded Andy Murray, who had a first-set lapse before beating American Ryan Harrison 4-6, 6-3, 6-4, 6-2.

Murray, who has lost in Grand Slam finals three times without taking a set, is attempting to become the first British man since Fred Perry in 1936 to win a major.

Andy Roddick easily defeated Robin Haase of the Netherlands 6-3, 6-4, 6-1 to also move into the second round. The 15th-seeded American broke Haase to go up 3-0 in the final set with a running passing shot down the line that left his opponent hitting his head with his racket. He broke Haase again to close out the match.

In night matches, Jo-Wilfried Tsonga, beaten by Djokovic in the 2008 final at Melbourne Park, defeated Denis Istomin 6-4, 3-6, 6-2, 7-5.

Another former finalist, Lleyton Hewitt, gave the night session crowd at Rod Laver Arena something to cheer when the Australian veteran beat Germany's Cedrik-Marcel Stebe 7-5, 6-4, 3-6, 7-5, coming from 5-1 down in the fourth set.

Earlier, No. 5-seeded David Ferrer advanced in straight sets, 6-1, 6-4, 6-2, over Rui Machado of Portugal. No. 17 Richard Gasquet, No. 23 Milos Raonic of Canada, No. 24 Kei Nishikori of Japan and No. 32 Alex Bogomolov Jr. of Russia also advanced.

Djokovic started his Australian Open defense wearing a pair of red, white and blue shoes with images of his three major trophies on the sides and a Serbian flag on the heels.

He gave up an early break but immediately broke back at love as he won the next 17 games, saving a break point in the opening game of the second set.

"I think it was a learning process for me in the last couple of years. I just have more confidence that I'm playing on right now," he said. "I just believe that I can win, especially against the biggest rivals in the major events."