Kim Clijsters is one of the friendliest players on the women's tour. Cheery in the locker room, generous, polite.

That's off the court.

She learned by losing three Grand Slam finals that intensity is essential to winning a major, something she's hoping to do outside the United States for the first time.

Clijsters started her Australian Open run with a 6-0, 6-0 romp Tuesday. Such domination is not uncommon in the early rounds of a Grand Slam tournament when top seeds face lowly ranked players, qualifiers or wild cards.

To do it, however, against three-time Grand Slam finalist and former No. 1-ranked player Dinara Safina was remarkable.

Safina had no answers for Clijsters, who sprayed winners all over the court. And Clijsters, a three-time U.S. Open champion, offered no letup.

"When you feel that your opponent is not playing their best tennis, you really just try not to focus on that too much," she said. "You try not to become a little bit more easygoing. ... You try to keep that same mentality as when you started 0-0."

Clijsters had been focused on the first round since last week's draw. She realized that even an injured and out-of-form Safina can spring an upset in the first round of a tournament left wide open by the absence of defending champion Serena Williams.

"I expect my opponent to come out and play their best tennis. She obviously didn't do that today," said Clijsters, who has won the U.S. Open twice since returning to the tour from a break to have a child. "But my attitude still was there to try and finish it off and not let her get back in the match."

The first-round match involving Lleyton Hewitt, Clijsters' ex-fiance, was altogether different — a 4-hour, 48-minute five-set loss to David Nalbandian that ended at 1:10 a.m. Wednesday.

Jo-Wilfred Tsonga, the 2008 Australian Open finalist, came back from two sets down for the first time in his career in another late five-setter.

Hewitt, a two-time major winner, usually revels in the late finish — he once beat Marcos Baghdatis in an Australian Open match not completed until 4:34 a.m. Nalbandian lost the 2002 Wimbledon final to Hewitt and the pair have a tense rivalry.

The Argentine drew begrudging applause from the parochial Rod Laver Arena crowd for his grit — he was a point from going two breaks down in the fourth; he wasted a chance to serve for the match in the fifth; saved two match points; then finished with a pinpoint lob as both players struggled with cramps and fatigue.

"What I take out of today? I take the brave heart that I put on the court," he said.

In 15 runs at the Australian Open, Hewitt's best finish was his 2005 final defeat. He'll be 30 next month. Australia hasn't produced a homegrown winner of the national championship since Mark Edmondson in 1976. The drought isn't likely to end soon.

Now all the talk in Melbourne will be about Rafael Nadal and his pursuit for a "Rafa Slam."

The Spaniard played only 11 games in his opening match Tuesday, the match curtailed because of Marcos Daniel's injured left knee. Not content to extend his Grand Slam string of 22 match wins with the 6-0, 5-0 scoreline, Nadal went to the practice courts to work on his serve. That's the element of his game he thinks he needs to improve to become the first man in 41 years to all four majors at once.

Laver last did it in 1969, in a calendar year. Nadal's bid for a "Rafa Slam" started a few months after he limped out of Melbourne Park last year with an injured knee after retiring from his Australian Open quarterfinal against Andy Murray. He won then won the French, Wimbledon and U.S. Open crowns.

He, like Clijsters, felt a pang for a struggling rival's plight. But he didn't show it as he moved his hobbling Brazilian player around the court with powerful groundstrokes. He said it never entered his head to give a point or two to Daniel.

"No. For sure I am a professional and I try my best in every point," Nadal said. "That's the best thing for respect the opponent in that situation."

Murray, who lost last year's Australian final to Roger Federer, didn't have to go three full sets, either. He was leading Karol Beck 6-3, 6-1, 4-2 when the Slovakian retired with a shoulder problem. No. 4 Robin Soderling defeated Potito Starace 6-4, 6-2, 6-2.

After lopsided first-round wins, Federer and 2008 champion Novak Djokovic are back in action Wednesday in the second round.

Federer plays Gilles Simon, whom he hasn't beaten in their two previous matches and is one of only three men on tour with a winning record against him. Djokovic of Serbia plays Ivan Dodig of Croatia in an afternoon match at Hisense Arena. Organizers and security will monitoring it closely to avoid any repeats of the clashes between rival Balkan fans that marred the 2009 tournament.

Nadal isn't interested yet in how anybody else is progressing, or how his own play is perceived.

"I never read a lot about me, so this is not an obsession. Seriously, the most positive thing that's talking about that is because I won the last three. The rest of the things doesn't matter," he said. "I am not ready to think if I am ready to win this tournament or not right now, no? I never think about winning the four Grand Slams in a row because that's very far right now."

Nadal next faces American qualifier Ryan Sweeting, who beat Daniel Gimeno 6-4, 6-4, 6-1.

On the women's side, the No. 1 and No. 2 ranked players have never won a major, leaving No. 3 Clijsters and No. 4 Venus Williams as favorites to advance.

No. 1 Caroline Wozniacki plays her second-round match against American Vania King on Wednesday. No. 2 Vera Zvonareva opened with a 6-2, 6-1 win over Sybille Bammer.

Ana Ivanovic, the 2007 French Open champion and 2008 Australian Open finalist, lost 3-6, 6-4, 10-8 to Russia's Ekaterina Makarova. Ivanovic finished the tournament at the same stage as Safina and 40-year-old Japanese veteran Kimiko Date Krumm, who had chances to beat No. 12 Agnieszka Radwanska in three sets.

Safina was less than pleased at her "embarrassing" performance, and didn't think she warranted any reprieves from Clijsters.

"Give her a game?" Clijsters said. "No, I mean, I do feel bad. I even caught myself like at 5-Love, she hit those couple backhands down the line, 'Yeah, that's it!'" she said, smiling. "But I wouldn't give her a game."