The 20-year-old Belgian, who won her first WTA Tour singles title here in 1999 as a 16-year-old qualifier, powered through the first set and overcame a 4-1 second set deficit to successfully defend her crown for the second year running.
Clijsters, who surrendered the top ranking to compatriot Justine Henin-Hardenne for a single week last Monday, has now won eight titles this year, as many as her fellow Belgian.
She was appearing in her 14th Tour singles final of the year, a feat last achieved by Steffi Graf 10 years ago.
"I can't believe I've won this tournament now four times," Clijsters said. "I came here as a 16-year-old, just starting out on the Tour and ever since it has been a big part of my career.
"And it sounds weird to say I've won eight titles this year... I've played a lot, but I've managed to stay consistent pretty much the entire season, so for me I'm just hoping I can continue that in a couple of weeks (at the season-ending championships) in LA (Los Angeles).
Despite losing the first set 6-2, Rubin continued with her net-charging tactics and they paid some dividends. The 27-year-old American, ranked 10th, surged to a 4-1 second set lead before Clijsters regrouped and clinched the win in 82 minutes.
RUBIN DISAPPOINTED
"After the first set Chanda really picked up her game -- she took advantage of her opportunities, while my level might have dropped a little bit," said Clijsters.
"But I kept my focus even when I was down 4-1 and I told myself I still had a chance to win that set," she added.
Rubin was understandably disappointed to lose in straight sets and intends to work on her game at the end of the season.
"It's always great to get to a final, but I suppose I'm a little disappointed I at least didn't push it into a third set," she said.
"I put myself in a really good position, going up 4-1, but I just didn't keep it going. Kim raised her game a bit and I just didn't respond well enough.
"I've been happy with the way I've played since the U.S. Open, getting to three finals. I'm just going to keep working hard, especially next week. Hopefully I can do well in Philadelphia and qualify for the championships.
"I'm very happy with the way my season has gone. I've won a couple of titles but over the break I'm going to work on my fitness and on the parts of my game that I need to improve even more.
"I'd like to just keep my play going into 2004, maybe with some better results at the grand slams."
In the doubles final, Maria Sharapova and Tamarine Tanasugarn defeated Elena Tatarkova and Marlene Weingaertner 6-1 6-4. They are now 8-0 as a team, having won the Japan Open earlier this month.
Sharapova won her first Tour singles and doubles titles in Tokyo.
