NEW YORK -- Her 10th double-fault hadn't even finished trickling down the net, but Venus Williams' eyes were already jammed shut in anguish and her shoulders sagged.

	'It's not that I thought I could win all three, I just said, "I'm tired of losing,"' Serena said.

One point later, when she pressured her sister into one final error, Serena Williams looked similarly stricken. She stood, bent over on the baseline, trying to catch her breath and compose her thoughts. There was a lot to process.

Serena bludgeoned her older sister off the court 6-4, 6-3 in the United States Open final on Saturday night. Serena was not merely, in the lexicon of tennis, too good. She was too great.

With the No. 1 ranking -- not to mention the gravity of history -- at stake, Serena prevailed in a cursory 72 minutes.

Factoring in her French Open and Wimbledon titles, she became the ninth woman in the history of women's tennis to win three Grand Slams in a single season and only the sixth to win them consecutively -- the "Serena Slam" she called it. Imagine if she had even played in this year's Australian Open. She sprained her right ankle the week before in Sydney and had to withdraw.

"I never thought about it until you just said it," Serena told a reporter in her post-match interview. "Oh, I could have, huh?"

Venus failed in her bid to win a third consecutive U.S. Open final, something that hasn't happened in nearly a quarter-century. Serena ended Venus' 19-match winning streak, a run that began after her conquest at Wimbledon, and a 20-match win streak here at the Open.

Where did Serena's resolve come from?

"I was just tired of losing," she said. "It's not that I thought I could win all three, I just said, 'I'm tired of losing. I'm not going to lose anymore.' Life was passing me by."

Afterward, Venus looked and sounded tired, period.

"My game went down after the fourth round," she said. "I just couldn't do a thing to bring it back up. After that, I posed and pretended that I was doing well, but I don't think I was doing as well as I would have liked.

"I don't now what it is. I just think I need t have a break, basically. I think mentally I'm not there as much."

	Venus' serve failed her Saturday night.

Venus, 22, and Serena Williams, 20, with their astonishing power and speed, have taken the women's game to a new place. Only another Williams, it seems, can apply enough pressure to reveal any dangerous flaws. Under the wicked glare of prime time, Venus' serve betrayed her; the 10 double-faults were killers and her weak second serve was cannon fodder for Serena.

Venus served 10 games and was broken five times. While Serena, pressing mostly from the baseline, had 17 break opportunities; Venus only had four. That, in essence, underlined Serena's dominance.

Venus watched here as Serena won the family's first Grand Slam in the 1999 U.S. Open, then went off on a tear, winning Wimbledon and the U.S. Open the next two years. Serena, suitably inspired, won this year's French Open and Wimbledon -- over Venus in the finals.

And so, Venus entered the match with some powerful motivation. You could see it in her wide eyes and pursed lips as Aretha Franklin sang "America." Was it fierce concentration -- or nerves? The latter, Venus' match-opening double-fault seemed to suggest. Three points into the match, and Serena was looking at three break points. Venus escaped, but it was a trend that eventually cost her the first set.

The crowd, perhaps sensing Venus' vulnerability, seemed to favor her over Serena. Afterward, Venus acknowledged that the blister that had developed during her semifinal match on her right hand, had crossed her consciousness. It didn't, however, seem to be a factor in the match.

In the seventh game, on her ninth break opportunity, Serena finally converted. Venus had already dumped another double-fault halfway down the net at 15-30 and now Serena stepped into another second-serve bunny and absolutely crushed a forehand that landed just inside the baseline.

And although Venus broke back in the next game, converting her second chance of the night, she was broken again in the next game. Again, the serve let her down. Her sixth double fault came at 30-40 and allowed Serena to serve for the set. An ace was, appropriately, the exclamation point.

With the second set at 1-all, Serena worked herself into another break point and Venus complied with yet another double fault, her ninth. In the fifth game, after a flurry of heavy shots, Venus sent a backhand long. It gave Serena a commanding 4-1 lead and the match appeared to be over.

Temporarily losing her focus, Serena let her older sister back into the match when her impatient backhand went long. Now, could she reel in another break of service? Uh, no.

Serena held easily, tossing in a 104-mile-an-hour ace and Venus' service game at 3-5 was her last. She saved two match points with an ace down the middle and an aggressive net charge, but in the end Serena put the hammer down, pushing her deep into a corner and forcing one last forehand into the net.

And to the victor went the spoils: The No.1 ranking, the check for $900,000 and a splendid sterling silver trophy.

Venus' demise, given her spotty play the last four matches, was predictable. While Serena breezed through the draw -- ultimately losing only 29 games in seven matches, an average of 6-2, 6-2 -- Venus had to work considerably harder to get to her third consecutive Grand Slam final. She actually dropped two sets along the way and lost 16 more games than her younger sister.

And after it was over, when Serena was sitting pretty in a pink warm-up suit in her post-match press conference, she had definitively separated herself from the rest of the game, including her sister, who happens to be the No. 2-ranked player. While there have been five different No. 1 players over the past 11 months in women's tennis -- Martina Hingis, Jennifer Capriati, Lindsay Davenport and both Williams' -- there is no longer any doubt who the best player is.

Serena now leads the series between the sisters 6-5 and has won the past four. The Grand Slam total is now 4-all -- and counting.

The 2003 Australian Open in Melbourne is up next. So, can Serena win them all next year?

"I have that focus," she said. "My goal now is to go Down Under."

Greg Garber is a senior writer at ESPN.com.