In dangerous Chilean Fernando Gonzalez, Roddick had the tougher test, and came through it manfully 6-2 7-5 7-6 (7/4).

Agassi was forced to deal with plucky Australian Todd Larkham, who briefly threatened by moving a break-up in the second set before the four-times Australian Open champion, who last lost a match at Melbourne Park in 1999, cleaned up 6-1 6-3 6-4.

Sixth seed Rainer Schuettler continued his disastrous run of form by throwing away a two-set lead to remain without a win in 2004 as Gilbert’s men took the honours.

For Roddick, entering the Australian Open as top seed is a new experience, but Gilbert is an old hand at dealing with such pressure.

“Brad’s philosophy is I’m not Andre and so he can’t approach me like he did with Andre,” said Roddick.

“We don’t talk about his relationship with Andre that much but just knowing he has been there before and he’s not going to get freaked out by any situation or surprised by anything is nice.”

Agassi’s committed preparations for the Australian Open are renowned and Roddick this year introduced the Kooyong invitational tournament to his schedule.

“He [Gilbert] thought that was good preparation and I agree after having been there,” said the 21-year-old US Open champion.

“There are a couple of things here and there but I don’t know if that is his work with Andre – he just knows the game really well.”

Roddick forced the upper hand in a tight encounter as Gonzalez became increasingly frustrated with some crucial line-calls.

“I’m happy to get through it, especially it could have easily been extended into four sets, and then it’s anybody’s game again,” Roddick added.

“I was just going for the win. I got through in straight sets with the the feeling that I can still improve a lot on my form.”

Along with Schuettler, seeds Arnaud Clement (30), Vince Spadea (29), Mardy Fish (21), Tommy Robredo (20) and Nicolas Massu (12) were all bundled out.

Schuettler surrendered a two set lead to Robin Soderling, going down 4-6 4-6 7-5 6-3 6-4.

“I’ve had a pretty tough three weeks now. I started in Doha, Sydney and now here. I didn’t win a match,” said the sixth seed.

As expected, Carlos Moya pulled out with an ankle injury suffered during Saturday’s final in Sydney and Younes El Aynaoui failed to finish his match.

The Moroccan could not play on against Spaniard Galo Blanco with the foot injury that ruled him out of Kooyong.

Russian Marat Safin made a successful return to the Grand Slam scene after an injury-plagued 2003 meant he missed the French and US Opens as well as Wimbledon.

The 2002 runner-up beat American Brian Vahaly in four sets 6-2 3-6 6-3 6-4 and hungers for success now he is back on tour.

“I didn’t come here just to make a couple of rounds and be satisfied,” he said.

“I will try to win it. Why not? I had a lot of months off and now I have the motivation to do well.

“I had some time off and you have a completely different view of tennis. I had a really good time off. That’s why I want to be back and I want to finish the year number one.”

It is certain that Brad Gilbert’s influence, in one way or another, will make that ambition a tough one for Safin to fulfil.