It may not have been the hottest day on record in Melbourne, but for Roger Federer to barely break sweat was still a notable achievement.

Against a player ranked 49th in the world and the reigning Australian Open doubles champion, Federer demonstrated precisely why he is an odds-on favourite to retain his title in Melbourne.

The world number one and top seed took just 93 minutes to thrash Fabrice Santoro for the loss of only four games, easing into the second round with a 6-1 6-1 6-2 victory.

It was the Swiss star's 23rd consecutive victory and talk of him winning all four grand slams in the same year for the first time since Rod Laver in 1969 looks less fanciful with every addition to the win column.

On the opening day of the centenary championships, Federer's potential quarter-final opponent Andre Agassi also progressed safely, the veteran American easing injury worries with a 6-4 6-3 6-0 victory over German qualifier Dieter Kindlmann.

Fourth seed and last year's beaten finalist, Marat Safin, was equally ruthless, albeit against Serbian qualifier Novak Djokovic, cruising to a 6-0 6-2 6-1 victory.

But fifth seed Carlos Moya, a potential semi-final opponent for Federer, was dumped out in four sets by Spanish qualifier Guillermo Garcia-Lopez. Playing only his second Grand Slam, the 21-year-old world number 106 recorded the shock of the tournament so far with a 7-5 6-3 3-6 6-3 victory.

Federer, who warmed up with victories over Tim Henman and Andy Roddick in the Kooyong Classic last week, declared himself satisfied with his performance.

''It was good, a good start,'' said the 23-year-old. ''I think the start of the match was important for me. That set the tone for the rest.

''And I never really gave him a chance to get back into the match. Best-of-five, an easy three-setter sometimes they look very, very easy, but I always had the feeling I still had to play some good points to win them, especially against him.

''He gets back a lot of balls. But I'm happy with my performance, and that's what counts in the end.''

Agassi pulled out of his exhibition match against Roddick last week with a tendon injury but was cleared to play after an MRI scan and was happy with his fitness.

The 34-year-old, scheduled to face Federer in the quarter-finals, said: ''Today I woke up feeling the best yet since it's happened. And with the assurance that I'm not going to sort of pull anything bad, I had the green light to push through anything I might be feeling.

''And that's what I did, I just pushed through a bit of stiffness, and then I felt like it loosened up nicely and I was okay.

''He didn't have a lot of weapons, but he made you work and I felt as the match went on I was getting more and more comfortable and better.

''It was a good first match for me but I have to be ready to step it up from here. I've always played well down here. Hopefully this year will be no different.''

Moya beat Garcia-Lopez in their only previous meeting earlier this year in Chennai, but had needed a third-set tie-break to get past his Davis Cup hitting partner in the semi-final.

''It is a big disappointment,'' the 1997 Australian Open finalist admitted. ''I was playing well before I came here.

Meanwhile, Serena Williams spent most of the off-season recording a television sitcom, but insists she remains deadly serious about her tennis.

Williams has made no secret of her ambitions to be a film star when she retires from tennis and has varied interests outside the sport, most notably designing her own eye-catching outfits.

But despite finishing last year ranked just seventh in the world - her lowest since 1998 - and without a Grand Slam title to her name, the 23-year-old is determined to defy the critics suggesting her time at the top is over.

Williams defeated France's Camille Pin 6-1 6-1 in just 56 minutes and warned: ''I definitely wouldn't be here if I didn't think I was a leading contender, I'd rather stay home."