MELBOURNE, Australia — Serena Williams was more subdued in her first Grand Slam match since her outburst at the U.S. Open.

Top-ranked Williams started the defense of her Australian Open title with a 6-2, 6-1 win today against 18-year-old Polish player Urszula Radwanska.

The victory was more like her previous match at Melbourne Park — a 6-0, 6-3 win over now No. 2-ranked Dinara Safina in last year's final — than her last in a major: her loss to Kim Clijsters in the semifinals at Flushing Meadows.

Her profanity-laced tirade against a line judge who called her for a foot fault cost Williams that match, a record fine of $82,500 and a suspended ban which means she'll miss a U.S. Open if she has another such outburst at any Grand Slam event in the next two years.

Williams has written about the fine being unfair, saying it wouldn't have been applied to a man in the same situation. But she has accepted it, set up a charity to raise an amount equal to the fines she received, and moved on.

"I always said what I did wasn't right, but I turned that around and I'm actually raising $92,000 to educate ladies, women, also for my school in Africa ... also I'm giving some money to Haiti," she said. "I don't know whoever got fined like that. People said worse, done worse. I just thought it was a bit much."

As for the suspended ban?

"No, that hasn't crossed my mind at all as if I yell too much, it would be a problem," she said. "I feel like I can always be myself.

"You know, I just do the best that I can. I'll say, 'C'mon.' I'll get frustrated. I'll still be human. I'll still make mistakes. I'll still learn from them."

The 28-year-old American hurt her left knee at the Sydney International last Friday night and later said she has been bothered by a foot problem.

Williams played with her right thigh heavily wrapped with a white bandage today, but said it was more for a precaution against injury than anything else.

Williams broke Radwanska in the opening game to set the tone. Even serving for the set at 5-1 and 40-0, she huffed when her forehand landed too long. Next point, she clinched the set with an ace.

Radwanska saved three match points before dumping a backhand into the net.

On the men's side, top-ranked Roger Federer struggled at times in his first-round match before beating Russia's Igor Andreev, 4-6, 6-2, 7-6 (2), 6-0.

Federer had some anxious moments, losing the first set after having his service broken in the ninth game, then having to save three set points in the 12th game of the third set before winning it in a tiebreaker.

Federer dominated the fourth.

Sixth-seeded Nikolay Davydenko had a 6-1, 6-0, 6-3 win over Dieter Kindlmann of Germany, advancing along with No. 12 Gael Monfils of France, No. 19 Stanislas Wawrinka of Switzerland and No. 21 Tomas Berdych of the Czech Republic.

Americans James Blake and John Isner reached the second round. Blake had a 7-5, 7-5, 6-2 win over Frenchman Arnaud Clement, while Isner held off Andreas Seppi of Italy, 6-3, 6-3, 3-6, 5-7, 6-4.

No. 9 Fernando Verdasco had a 6-7 (4) 7-6 (1), 7-5, 6-2 win over wild-card entry Carsten Ball of Australia.

Fabrice Santoro extended his Grand Slam career into a fourth decade, but he lasted only one match — a 7-5, 7-5, 6-3 loss to 14th-seeded Marin Cilic of Croatia.

The 37-year-old Frenchman, who started his Grand Slam career at the 1989 French Open, retired last season but returned to Melbourne Park this year.

American Sam Querrey, seeded 25th, lost to German veteran Rainer Schuettler, 6-3, 2-6, 6-4, 6-3.

Ana Ivanovic, who reached the Australian Open final and won the French Open in 2008, opened with a 6-2, 6-3 win over American Shenay Perry.

Elsewhere, No. 8 Jelena Jankovic, No. 11 Marion Bartoli, No. 13 Sam Stosur and No. 19 Nadia Petrova advanced along with No. 26 Aravane Rezai.

No. 18 Virginie Razzano lost, 6-2, 6-3, to Russia's Ekaterina Makarova and American Vania King ousted No. 23 Dominika Cibulkova of Slovakia, 6-3, 6-7 (5), 7-5.