Just being Serena Williams was more than enough on a balmy New York night for the 20-year-old to crush the twice-defending champion 6-4 6-3 in 72 minutes.
"It makes me run fast... jump high... like a cat," she grinned when asked about the skin-tight, black cat-suit she unveiled here last week and calls her Catwoman suit.
But in truth, she needed neither ability to any real extent as she strolled past an under-par Venus to bank $US900,000.
"I am just elated, now. Thanks daddy and thanks mom and all my sisters too," she said as she collected the silver trophy. "Right now I am just so happy. My parents are the backbone of our family."
Serena, who missed January's Australian Open with an ankle injury, has now beaten Venus in the final of the last three Grand Slams, adding the US crown to her French Open and Wimbledon titles.
The victory sees her hold on to her world number one ranking and avenged defeat in the final here last year.
Only six other women in the history of the sport had won three majors in a row Steffi Graf, Martina Navratilova,
Billie Jean King, Margaret Smith, Maureen Connolly and
Helen Wills back in 1929.
Serena etched her name into the record books with a ferocious floodlit performance.
"If I win in Australia it will be a Serena Slam," she smiled.
Serena looked the stronger from the start, latching on to Venus's serve and punching winners at will.
She broke through in the seventh game, cracking a forehand winner to take her sister's serve.
Venus broke back immediately but could not hold her serve again in the set and Serena served out with a 105 miles per hour (169 km) ace to ease ahead.
With a pink headband and wristbands, but not the Pink Panther shirt she wore to wow the New York crowd earlier in the week, Serena broke again for a 2-1 lead in the second set when Venus threw in her ninth double fault.
The match, and title, was slipping from Venus's grip as the champion here in 2000 and 2001 ran out of ideas. She managed to fight off two match points while trailing 5-3 with a second serve ace and a firm volley, but her 10th double fault gave Serena a third.
The 20-year-old top seed made no mistake this time, forcing Venus into a forehand error to clinch the title.
In Paris, Venus joined the photographers snapping away at her sister after June's French Open final. On Saturday, it was
father Richard who joined them to take pictures of his youngest daughter collecting the trophy she won in 1999.
Venus was left to rue another defeat to a sister who is pulling away at the top of the world.
"I just wasn't the better player today," she said. "I'm proud of her. I know what it is like to be playing better than everyone else. She's had a great year."