Serena Williams came back from a set down to beat Kim Clijsters 2-6 6-3 6-3 in the final of the Toyota Princess Cup in Tokyo.

It was the world number one's seventh WTA tour title of the year.

The newly crowned US Open champion recovered after an error-strewn first set, finally breaking Clijsters in the eighth game of the second.

Williams, who turns 21 on Thursday, was in complete command after that, wrapping up the match in one hour and 35 minutes.

Victory saw her tie sister Venus for the most singles titles on the Tour in 2002.

Delayed

Serena has also won the last three grand slams of the year.

"I feel great," she said after her win over third seed Clijsters.

"It was a great final and I don't think the tennis could have been any better than it was today."

The start of the match was delayed by 20 minutes when organisers decided to close the retractable roof at Ariake because of rain.

After the second game of the first set there was another delay when the floodlights at the multipurpose arena went out.

Williams, who also won the title in Tokyo on her only other appearance in 2000, picked up a cheque for $93,000, taking her 2002 prize money to almost $3.2m.