Serena Williams put herself back on top of the women's world rankings with a 6-3 6-2 victory over Russian Ekaterina Makarova in the second round of the $6.6 million China Open today.

Her American compatriot and defending men's champion Andy Roddick, however, was humbled in his opening match, falling to a 6-2 6-4 first round defeat at the hands of Polish qualifier Lukasz Kubot.

Dinara Safina's defeat to 226th-ranked Chinese wildcard Zhang Shuai yesterday had left the way open for Williams to end the Russian's 25-week reign as number one and she never really looked like blowing her chance.

The American second seed was broken in her first service game and made a meal of her last but converted her fourth match point to seal the victory, raising a single finger in the air in celebration of her return to the top.

"I'm really excited," said the 28-year-old. "Obviously I'm happy to be there because I've worked so hard this year to get there. I think I've earned it." -  Reuters