The doping storm created by Greg Rusedski's positive nandrolone test remains the number one topic in tennis as the Australian Open refuses to produce an upset.

Guillermo Coria's defeat remains the only major surprise in the tournament as the the major seeds continue their march towards the second week.

Defending champion Andre Agassi, world number one Andy Roddick and all the leading seeds progressed into the third round at Melbourne Park yesterday.

However, the draw is beginning to throw up some spicy encounters, with Roddick set to face fellow big-hitting American Taylor Dent and Paradorn Srichaphan up against exuberant Brazilian Gustavo Kuerten.

Agassi will meet the 1999 runner-up, Thomas Enqvist, after a quick-fire straight-sets victory over Czech Thomas Berdych.

The defending champion stunned the 18-year-old 6-0 6-2 6-4 in just one hour 22 minutes, stretching his unbeaten run at Melbourne Park to 23 matches, but rated his opponent as a hot prospect for the future.

''I thought that was a high standard match,'' said Agassi.

''Sometimes the scoreline is not reflective of the work that's going into a match. I was coming up with the right shots at the right time.

''I like his game a lot. He's going to be a real good player.''

Roddick thumped Bohdan Ulihrach 6-2 6-2 6-3 but was warned by Agassi that Dent, the 27th seed, will be a far tougher proposition.

The 22-year-old battled through five sets to beat Juan Ignacio Chela 3-6 6-4 4-6 7-6 (7-4) 7-5.

''Taylor has a lot of firepower off the serve and groundstrokes, he's very athletic at the net and has great hands,'' said Agassi.

Kuerten, three times a French Open champion, had never progressed further than the second round on Melbourne Park's Rebound Ace surface before yesterday. The Brazilian beat Ivan Ljubicic 7-5 6-7 (5-7) 6-4 6-3 to reach unchartered territory here.

Others to secure second victories included American veteran Todd Martin, who battled past Ivo Karlovic in three tie-breakers 7-6 (7-4) 7-6 (7-4) 7-6 (9-7) and will now face Marat Safin after the Russian beat Jarkko Nieminen 7-6 (7-5) 6-4 4-6 6-4.

Frenchman Nicolas Escude overcame Rainer Schuettler's conqueror Robin Soderling 6-3 7-6 (7-4) 6-4 and will face 32nd seed Robby Ginepri of America.

In the women's event, fourth seed Amelie Mauresmo is in such devastating form she believes the Australian Open title could be hers for the taking.

The French 24-year-old, losing finalist to Martina Hingis here in 1999, has dropped only three games en route to the third round and yesterday took just 44 minutes to beat the world number 64 Ludmila Cervanova 6-0 6-2.

Mauresmo's quest for a first Grand Slam title has been made significantly easier by the absence of leading women Serena Williams, the defending champion at Melbourne Park, and Jennifer Capriati.

Nevertheless, Kim Clijsters and Venus Williams are in the other half of the draw, while world number one Justine Henin-Hardenne and former champion Lindsay Davenport both won through to the third round yesterday.

Henin-Hardenne was able to defy a stomach bug to score a 6-1 6-4 victory over Camille Pin, while fifth seed Davenport needed three sets to beat the plucky Emilie Loit.

Scores - Men's Singles 2nd rd: Nicolas Escude (Fra) bt Robin Soderling (Swe) 6-3 7-6 (7-4) 6-4, Jurgen Melzer (Aut) bt Galo Blanco (Spa) 6-3 6-4 6-3, Todd Martin (USA) bt Ivo Karlovic (Cro) 7-6 (7-4) 7-6 (7-4) 7-6 (9-7), (4) Andre Agassi (USA) bt Tomas Berdych (Cze) 6-0 6-2 6-4, James Blake (USA) bt Nicolas Lapentti (Ecu) 6-3 7-6 (7-4) 2-6 6-1, (19) Gustavo Kuerten (Bra) bt Ivan Ljubicic (Cro) 7-5 6-7 (5-7) 6-4 6-3, (9) Sebastien Grosjean (Fra) bt Jan-Michael Gambill (USA) 6-4 6-3 6-2, Dominik Hrbaty (Svk) bt Gaston Gaudio (Arg) 6-1 7-5 6-0, (1) Andy Roddick (USA) bt Bohdan Ulihrach (Cze) 6-2 6-2 6-3, Thomas Enqvist (Swe) bt Karol Beck (Svk) 7-5 4-6 6-3 6-4, Olivier Patience (Fra) bt Nikolay Davydenko (Rus) 7-6 (7-2) 6-7 (7-9) 6-3 6-2, (27) Taylor Dent (USA) bt Juan Ignacio Chela (Arg) 3-6 6-4 4-6 7-6 (7-4) 7-5, (16) Sjeng Schalken (Ned) bt David Ferrer (Spa) 6-3 6-2 5-7 6-1, Marat Safin (Rus) bt Jarkko Nieminen (Fin) 7-6 (7-5) 6-4 4-6 6-4, (13) Paradorn Srichaphan (Tha) bt Jerome Golmard (Fra) 6-3 ret, (32) Robby Ginepri (USA) bt Chris Guccione (Aus) 6-4 6-3 6-3

Womens Singles 2nd rd: (30) Svetlana Kuznetsova (Rus) bt Antonella Serra-Zanetti (Ita) 7-6 (7-0) 6-4, Aniko Kapros (Hun) bt Samantha Stosur (Aus) 6-3 6-1, (4) Amelie Mauresmo (Fra) bt Ludmila Cervanova (Svk) 6-0 6-2, (19) Eleni Daniilidou (Gre) bt Cara Black (Zim) 3-6 6-0 6-1, Mara Santangelo (Ita) bt Barbara Schett (Aut) 7-6 (7-3) 0-6 6-3, Anabel Medina Garrigues (Spa) bt Yuliana Fedak (Ukr) 6-2 2-6 6-3, Petra Mandula (Hun) bt (24) Magdalena Maleeva (Bul) 6-7 (6-8) 6-2 6-3, Claudine Schaul (Lux) bt (21) Elena Bovina (Rus) 6-4 6-3, (32) Fabiola Zuluaga (Col) bt Mariana Diaz-Oliva (Arg) 6-3 6-4, Jill Craybas (USA) bt Jelena Jankovic (Ser) 6-4 2-6 8-6, (1) Justine Henin-Hardenne (Bel) bt Camille Pin (Fra) 6-1 6-4, Vera Zvonareva (Rus) bt Melinda Czink (Hun) 7-5 6-4, Nicole Pratt (Aus) bt Akiko Morigami (Jpn) 1-6 6-3 6-3, (5) Lindsay Davenport (USA) bt Emilie Loit (Fra) 6-3 3-6 6-0, Alicia Molik (Aus) bt (15) Daniela Hantuchova (Svk) 6-4 6-3, Laura Granville (USA) bt Evie Dominikovic (Aus) 6-2 2-6 6-1.