'The only scary thing about winning a Grand Slam five weeks into your comeback is coming up with an encore,' Clijsters said at the time. 'I don't know how I'm going to top this, but it's a challenge.'

PARIS It was the year of the comeback in women's tennis.

Serena Williams bounced back from mediocrity to regain the No.1 spot, Maria Sharapova returned to action with some success after months of injury and, above all, Kim Clijsters won the US Open weeks after coming out of retirement.

It was the popular Belgian's emotional triumph in New York in September that was the storyline of the year.

A burned-out Clijsters retired in May, 2007, subsequently marrying and giving birth to a baby girl.

But the fire still burned within and when she announced her comeback in March, the feeling was that she would be unable to replicate her form of old.

However, that was exactly what she did do winning the US Open title for the second time, after her 2005 victory - her only Grand Slam title before retiring.

The manner of her victory was all more spectacular in that she defeated both the Williams sisters en route - Venus in a roller-coaster quarter-final and Serena in a semi-final that was the match of the tournament.

When Clijsters then celebrated on court with daughter Jada and husband Brian it brought the house down and sealed her position as one of the most popular tennis players in recent times.

'The only scary thing about winning a Grand Slam five weeks into your comeback is coming up with an encore,' she said at the time. 'I don't know how I'm going to top this, but it's a challenge.'

Clijsters is now hard at work preparing for that challenge - an assault on the Australian Open title in January in Melbourne where she is already known as Aussie Kim following her long romance with Lleyton Hewitt.

If Clijsters won the popularity parade, it was Serena who ended all argument about who is the world No.1 with her Grand Slam titles in the Australian Open and Wimbledon capped by taking the season-ending WTA Tour Championship in Doha.

For much of the year, the top spot had been held by towering Russian Dinara Safin due to her regularity in the tournaments outside of the Grand Slams.

But few believed she deserved the accolade and the pressure to produce began to tell on her to the point that she could barely get past a first round by the end of the year.

In Doha she lasted just two games and 13 minutes before a lower back injury forced her out in tears to ponder what had gone wrong.

'I don't care anymore. They can say whatever they want,' a disconsolate Safina said of her detractors,

'I have been in three Grand Slam finals and I've been in two semis. It's there. Last year I was winning every tournament and they were asking me why I'm not No. 1.

Serena, meanwhile, was radiant.

She badly sullied her reputation at the US Open with a foul-mouthed tirade against a line-judge who foot-faulted her in the tie against Clijsters effectively ending the match.

The American was eventually fined a record 175,000 dollars with the amount to be reduced to 82,500 dollars if she stays on good behaviour over the next two seasons.

By the time Doha came around, Serena had gone some of the way toward restoring her reputation with a global charm offensive wrapped around the launch of her autobiography 'On The Line.'

And in the Gulf, she blew away the opposition to lift the tour title once again defeating sister Venus in the final as she had done at Wimbledon.

Sharapova was, for once, less high profile, preferring to slowly rebuild her aching shoulder and shattered confidence with a series of lesser tournaments.

The three-time Grand Slam champion had been out of action for nine months and concerns had been raised that the biggest draw in the women's game could be facing an premature end to her career.

The Russian finished the year still somewhat short of her very best but she won in Tokyo and reached the final in Toronto to give enough indications that she has a chance if the shoulder holds up.

The year's other Grand Slam title at the French Open went to Svetlana Kuznetsova who defeated Safina in another one-sided Paris final.

Late in the year the comeback saga took another twist when former World No.1 Justine Henin announced that she would return to action in Australia.

However, 2010 will not see former world number one Amelie Mauresmo on court.

The 30-year-old Frenchwoman, who won Wimbledon and the Australian Open in 2006, announced her retirement.