When Dinara Safina replaced Serena Williams at the top of the women's world rankings in April, the Russian said she had achieved a childhood dream.

Tuesday, 24 hours after a shock opening round defeat in Beijing, Safina handed top spot back to the American having spent much of the intervening six months trying valiantly to prove she was no mere impostor.

Safina is not to blame for a complex ranking system but sadly for the often volatile Muscovite her failure to garnish the world number one tag with a grand slam title will leave question marks hanging over her reign.

Women's tour chiefs have jumped to the defence of Safina, the younger sister of former men's number one Marat, who won two grand slams, saying the ranking system rewards consistency.

However, they will surely be more comfortable with an 11-times grand slam champion sitting top of the heap.

Then again, Serena's public image took a battering at the U.S. Open last month when she imploded in her semi-final against Kim Clijsters and launched a foul-mouthed tirade at a female line judge.

Having already received a warning for smashing a racquet, Williams was handed an automatic point penalty, which gave Clijsters the match.

With disciplinary action hanging over her head, Williams could even find herself banned from the first grand slam of 2010 in Australia, where she crushed Safina in this year's final.

That would be a nightmare scenario for the WTA Tour.

RIGHTFUL PLACE?

Whatever the rights and wrongs of the ranking system, WTA President David Shoemaker said recently that the Safina/Serena debate had been good for the game.

"I think it helps us," he told Reuters last month.

"I think as much discussion as there is about who ought to be the number one ranked tennis player in the world is fabulous.

"I've heard just as many people who have argued that it should be Dinara Safina on the basis of her consistent performance versus whether it should be Serena Williams based on her success at the grand slams.

"If it gets written about or talked about on television then I'm more the happier. I think anything that generates that kind of interest in women's tennis is good for our sport."

Serena's routine victory over Ekaterina Makarova in the second round in Beijing Tuesday means she will reclaim what she believes is her rightful place in women's tennis when the WTA computer churns out the next rankings list.

While few who follow tennis will disagree that she is still the dominant force in the women's game, the treatment of Safina over the past few months has often been cruel.

While wearing the No. 1 badge the Russian powerhouse has collected three titles, including back-to-back claycourt crowns in Rome and Madrid and she also reached the Wimbledon semi-finals for the first time despite fighting her game.

Unfortunately, when her big chance to ram the words of her critics back down their throats presented itself at Roland Garros she completely fluffed her lines.

'TOO PUMPED'

She had looked the real deal as she blazed into the quarter-finals for the loss of just five games but having reached the final against compatriot Svetlana Kuznetsova she choked, ending an error-strewn loss with a double fault before breaking down in tears.

"I knew it was in my hands ... I was too pumped," Safina said recently of her French Open disappointment.

A humiliating 6-0 6-1 semi-final loss to Venus Williams in the Wimbledon semi-finals was followed by a patchy U.S. hardcourts campaign that culminated in a third round defeat at the U.S. Open by little-known Czech Petra Kvitova.

Safina also suffered the indignity of being bumped off the show court at the grand slam.

By then it was clear that the number one ranking was becoming a burden and her loss this week may have been greeted by a secret sigh of relief in the locker room.

At least now she can concentrate on winning a grand slam title free of the added pressure that came with trying to justify her top billing.

"One of my goals was to be number one, which I did. Now all my focus is on winning a grand slam. Once I win one I could go on and win many," she said recently in Japan.

Winning that maiden grand slam, however, has suddenly become a much tougher proposition now that Clijsters, the newly-crowned U.S. Open champion, and Justine Henin are back in the mix.

The absence of the Belgians left a void in the women's game that the likes of Serbs Ana Ivanovic and Jelena Jankovic and then Safina capitalised on.

With Clijsters and Henin, who will return next year, back on the circuit, the scrap to be top of the rankings promises to be a fascinating one.

(Editing by Peter Rutherford)