World number one and top seed Serena Williams starts as firm favourite to repeat last year's triumph at the Rome Masters women's event which starts on Monday.

No female player has successfully defended the title since Spain's Conchita Martinez in 1996.

The 21-year-old American has been in unstoppable form recently, winning tournaments in Paris and Miami as well as the Australian Open in January -- her fourth Grand Slam title in a row.

While Williams comes to Rome rested, her two big rivals for the title --- Belgium's Kim Clijsters and Justine Henin-Hardenne -- will arrive  in Rome only after disputing the final of the German Open in Berlin on Sunday.

In the absence of elder sister Venus -- whom Serena is avoiding in the run-up to the French Open at the end of the month -- the most dangerous threat should come from the Belgians.

Second-seeded Clijsters finished 2002 as the only player to have beaten both Williams sisters, while third seed Henin-Hardenne was last year's losing finalist.

Some of the pace of Williams's big-hitting game should be dissipated on Rome's slow clay courts, giving her adversaries a chance to fight rallies from the back of the court.

Clijsters's Berlin semi-final victory over Jennifer Capriati on  Saturday -- her first ever against the American -- lifted her above Venus Williams to number two in the world rankings.

Fifth seed Capriati, however, remains a constant threat on the tour. The 27-year-old American has reached at least the semi-finals in her last five tournaments.

Powerful fourth seed Amelie Mauresmo is also expected to progress to the later rounds, though the Frenchwoman -- who was runner-up in Rome in 2000 and 2001 -- still suffers lapses in concentration and sudden dips in confidence.

All top eight seeds have been granted byes through to the second round, where they look set to face soft opposition.

Williams and Henin-Hardenne have a chance to warm up against qualifiers, while Clijsters takes on the winner of the match between Austria's Barbara Schett and Italian Antonella Serra Zanetti.

The first-round draw did, however, throw out one intriguing contest featuring Yugoslav ninth seed Jelena Dokic and four-time Rome winner Conchita Martinez.

The veteran Spaniard dominated Rome's clay courts between 1993 and 1996.

The pair last met in Rome two years ago in the semi-finals -- a game Dokic won on her way to claiming the title.